My company has a tech convention every year. Last time I went I played spot the tech person - most people there failed the test (they were former engineers now in management trying to pretend they were still technical). I'm a staff engineer and I was the lowest position person I saw there - not even senior engineers much less the low or mid level engineers that would benefit from talking to the seniors at a tech conference.
You could be right, though I didn't spot very many I couldn't identify, it could be just what I was looking for. The company is selling to tech people in the company as a tech conference, but that doesn't mean that is really the point. (though I would expect the majority of our customers are not technical people, and thus I don't see how there is value in bringing customers in)
There are community open source and adjacent conventions that don't really have customers or, necessarily, many managers there. I'll be at one in a couple weeks. But directly company-run events are absolutely about generating leads/business. A lot of foundation-led events are somewhere in the middle.
I'd categorize both those groups as being "in tech." Even if they're not active developers, they're certainly tech-adjacent especially in the software space.
There are probably counter-examples, but I'm not sure where I'd go if I were, say, an enthusiastic amateur physics or chemistry enthusiast of some sort that would be especially accessible.
