There are three sides of the triangle which can move - the percentage unemployment, the number of hours per employee, or the total amount of consumption. Historically, people have simply consumed more - luxury is addictive, and people measure each other relative to what others in their community have.
However, there is a major counterbalancing force to efficiency gains - that there are only finite natural resources, and many easily accessible reserves are becoming depleted. Reserves of fossil fuels and high grade ores are declining fast, so increasingly more labour is required per unit of energy or metal - and the cumulative effects of pollution rise with accumulation over time and a rising population, more labour is required to prevent pollution.
Any natural resource that gets scarcer even as demand for it increases naturally gets more expensive. This gives people incentives to avoid its use, either by being more efficient or substituting alternatives.
This has even worked for land itself. As land gets more expensive as more people wish to live in an urban area, buildings add stories, using the same land over and over again.
To prevent pollution, we need workers producing LED lights instead of wasteful incandescents or mercury-laden (and ugly) compact fluorescents.
I have - and they are insanely expensive (okay thats to be expected) but what is worse is that they give very, very little light, not enough to light even a dinner table, let alone a small room.
Those compact fluorescent lights? Yeah not only do they flicker (which is bad for your eyes, even though it is not fast enough that you can see them just like the old CRT monitors) and there is some evidence that they may be linked to eye cancer, but even if they aren't they take about 30 seconds to turn on fully, which means I have to walk the corridor in the dark (what then is the purpose of lightning? fuck if I know). We don't need LED lighting, we don't need compact fluorescent lighting, we need actually useful lighting, which means incandescent light bulbs for at least the next 30 years.
Call me back in 2040 and we can try again.
As a society we're not doing a great job of helping workers move on. In any case, it really shouldn't be up to startups to protect jobs, any more than car companies had to compensate carriage manufacturers or nail factories helped blacksmiths.
You go to school for 12 years, then possibly uni for 3-7, then are unlikely to receive more than a couple of months of formal training throughout the rest of your life, even if you change careers.
Virtually nobody does a university course after graduating. I don't think that's because university is useless (though there is room for improvement), or that skills are easy to obtain elsewhere, but a society that tries to load a lifetime of study onto people who don't even know what they are going to be when they grow up.
But then TV came along and created even more jobs for the unskilled than the patent crop rotator over destroyed.
In the first call-center I worked in, I was doing financial support for customers. I was great at my job because I was studying finance at that time in my life. Everyone else on the 200+ team (excluding this very smart girl that came from a crappy neighborhood with crappy parents) were complete and utter retards. The place was a petri dish of fraud, bad advice, and foul phone manners.
In the second call-center I worked in two departments. The first one was sales, basically 300 kids just out of school tricking customers into promotions they did not want and hanging up on clients when they couldn't get a credit card number. I was also great at sales because I developed a system, without bullshitting the customers. I always hit the bonuses... but the rest of the department also hit them, with 500% my performance. Imagine I sold 10 units per day to hit 60 units a week (the bonus being after 50 units sold), they sold 300. Fraud to the extreme (and I know this because a close friend of mine did this... his whole team did). Lastly I did tech support. I was probably one of the few (less than 10) people that actually understood the technology. The rest of the 120 strong department where tech illiterate.
Aside, I strongly remember one agent being fired because he brought two machetes into the office building and cut (superficially, no horror story here) some dude's arm, and a 45 year old lady agent that reported 13 cases of sexual assault (the lady was hideous looking and was just looking for an easy payday) which got the 13 men fired and which ended with her resignation which included a severance pay of several thousand dollars.
They funniest side, is that at least 60% of all the agents I met, could not speak or even comprehend decent english. I thought that might be a prerequisite to do customer support/sales for english speaking customers. In comparison, I was once reprimanded for speaking french to the french speaking husband of a customer about their tech equipment.
So yeah, I say bomb all these call-centers. I don't live in the US, but I think that those sales agent jobs dealing with people in the US should be filled with US sales agents. Those tech support jobs for US customers should be filled with US college kids or recent graduates. Instead companies pay 300~400 dollars a month to a bunch of retards (I can count myself in this group, though give me a break I had been kicked out of my house so I took the first job I was offered), cheats, and thieves, so they can go ahead and make your experience on the phone a living hell.
I made a few hundred dollars in off-the-books employment for a borderline psychopath who nearly killed me with a pipe to the head. Following poorly planned unemployment brought on by the pipe incident, I got a job at a call center for an office supply company (the kind that sells things like, I don't know, staples). I remember those years pretty fondly: they paid me what I was owed in a timely fashion, no pipes were thrown at my head, I touched no toxic chemicals in a hot warehouse, and it was a value-creating job which I was good at for a wee bit of time prior to going to bigger and better things.
Hopefully he isn't secretly dreaming of firing the person who answers the phones as a triumph of the information age.