If you have a lot of money it’s fun to LARP the startup life. The experience working for such a company is highly varied and completely depends on the personality of the founder. But even if it’s a healthy place, it’s usually a black hole from a career development POV.
Don't confuse a hobby business with a failing business.
Plenty of people with independent means run loss making businesses for fun and/or support wives/children doing just that.
Have you ever wondered why kids climb trees?
It doesn't matter if it costs a lot of money to maintain. Yachts and sports cars do the same. That's actually like the whole point of it, after all.
I have been on the other side of this, building a frontend that connected to an external service robot that we, with a 5 minute script, managed to successfully prove internally was just a if/then/else state machine.
We got paid to make it, so we didn't care, but we knew someone was losing money.
It could’ve been worse, it could’ve been a fraud! But it’s merely a business designed to lose money. It won’t land you in jail but it’s not a place anyone would advance a career.