It of course depends on the country how things are implemented, but here there is a central insurance fund that all employees pay into. Then when an employee needs to take time off for parental leave the company applies to the fund and the fund covers the expenses. The company can then choose to pay out more than the fund does, or not. As is normal for benefits. This means though that every employee has a right to at least 16 weeks of leave at somewhere between 70-100% of pay. Details change the specifics.
Healthcare has little to nothing to do with companies. Technically you can sometimes get a discount by applying to a group scheme through your work, but mostly it is done independently. It costs about €170 a month a person. Depending upon how much you earn you can get a subsidy from the government for up to 100% of your monthly expense. That €170 covers most things you could need healthcare wise, although somethings aren't covered unless you buy addons, for example eyeglasses. Everyone is required to have health insurance.
I guess this is why lots of startups use 'contractor' services because things like cleaning are not their core competency but what you describe could apply to many early stage startups. In that stage many companies are in a vulnerable position and death is likely. What you describe would only further reduce the chances of the company surviving. If all we have are entrenched businesses that can afford these additional expenses we end up in stagnation over time. Maybe thats one part of the reason why we don't see many big shot companies coming out of Europe today? I don't know.
On the other hand, €170 a month seems very reasonable. From a quick search it seems like in the US the average monthly healthcare cost covered by an employer is around $1,100 or around $13,200 per year. This is in additional to the portion that employees may have to pay. This varies depending on employer and plan.
How would pensions work? That is actually what I really wanted to know about. Pensions would be an additional added cost and it seems like only the big established companies can afford to offer it.
As for pensions it depends a lot on the specifics of the company. There are state run pensions here in the NL. Additionally you have some that unions, or the government have negotiated industry wide. So if you are involved in hospitality, restaurants, and similar then there is a special pension that automatically gets paid into every month. I don't really know the specifics because I'm not part of said pension.
The state pension is somewhere between 700 (each if in a couple) or 1100 (if single) a month. This is then supplemented by private pensions which are afaik basically required to be offered by all companies, even if they aren't created equally, and as mentioned above there are special industry or union pensions. Then add in things like socialized housing (which is much nicer than in the US or UK), and the lack of need for a car here and you can get by much more easily.
