Having a partner doubles your income. More, if French taxation works in any way similarly to the German system, then an official relationship puts you in a different taxation category. Having children moves you into yet another category where your net income noticeably improves. You're probably making an equivalent of 100K for a single person without realizing it.
>> And yet these startups, everywhere, are able to do exactly that. They use equity as a carrot to lure experienced people from a sure thing all the time.
Not really. Everywhere where I've been I've only seen kids writing code. Anybody who is senior has always been an independent contractor, and it's usually them who actually advance the work by leaps and bounds. But those, today you have them working for you, tomorrow they're elsewhere. And with the young and inexperienced, you won't accomplish much.
Also, experienced people with families usually ignore any talks about equity and start the initial offer analysis with a calculator in their hands. I'm yet to encounter a true senior specialist with family obligations that takes equity over hard currency.