Fun fact, a friend was complaining to me about how hard it is to hire Android engineers, because he keeps getting outbid by Uber. He's at a public company, by the way, but couldn't match their pay packages (including ~$1m in stock options).
Yes, you won't necessarily see the same crazy run up in stock value as if you joined at the ground floor, and yes, you'll owe taxes on the nominal value of the option price, etc... but that's still a lot of money, and it's arguably de-risked relative to an A-series startup. (Then again, if the company you're looking at isn't profitable, maybe it's not de-risked... buyer/employee beware.)
Oh well, you lose long term capital gains tax benefits, but most people do not have the money to even exercise their vested options, so they sell during IPO and have equivalent tax treatment as an RSU.
Some companies now have option expiry dates at 7 years, but those can be counted on one hand.
Joining a smaller company gives you the chance at a massive payout of $10M+ - but I'd bet your 4-year "expected value" would be much less than joining a bigger company. For one - your options are going to be worth anywhere between $0 and $1B - but heavily weighted towards zero. Two - you have to actually buy your options with cash, which reduces mobility because this is very risky! This often costs $20k or more. So you may leave your options on the table. Very few people would be leaving options on the table at somewhere like Uber today if they quit. You'd find the money and buy your shares. Three - your potential exits are numerous but many of them are the sort of deals that kind of devalue your equity to near worthless (due to LP) and instead buy the team with employment offers and new golden handcuffs - which can be highly variable. An IPO or mega acquisition is a clean transaction for common stock holders.
I think part of this scenario is that companies raising tens or hundreds of millions at billion++ valuations are hiring "scaling talent".
Scaling as in hiring many good to great people, but lots of them, some of whom overlap. Multiple product managers, many great engineers, great heads of sales/ HR/ operations.
Oftentimes they are focused on becoming huge, scalable, consistently growing revenue generating operations.