In my last search, the series D+ and public offers were good, and the startup offers were just laughable. I couldn't justify going to any of them just to make a bunch of other people rich.
My friends in similar situations take exactly the options you described. Some become founders (getting 30-40% of a company), some are angel investing (and sometimes joining a company they've invested in "for fun"), some just can't handle the bureaucracy beyond 100 people and join startups, and the vast majority are at larger public companies or startups that are nearly there.
I really believe there's an imbalance that's due for a correction, because skilled and experienced people mostly avoid startups right now. Early valuations may need to increase, employee equity pools will need to increase, equity terms must become less confiscatory, team sizes should shrink, and timelines to exiting must decrease. Will it happen? I'm not sure. It depends on whether startups can continue to coast on the pool of less-skilled engineers joining the true believers.