You are less than 3 years into your career, and you think you have worked for some of the best companies, and yet you are unhappy. How do you know you have worked for some of the best for you? You are going by names.
My guess is that you are talking about hot valley companies, and guess what? In those, someone with little experience will not get to work on anything fun, because they have enough talent that almost everyone is batting below their weight. You see similar things in startups where there is no challenging technical component to the business: If all you need to do is scale an app that is just a bunch of forms, then guess what? it will be boring. Go work at a company that is doing science instead, and then tell me it's boring.
You complain about compensation peaking early, as if that's a bad thing. In the US, 300K is not insane for senior devs, and that doesn't count miraculous exits. Many doctors don't make that, and they had to pay for a lot more education, and handle the terrible life of the resident before they can get to real money: And let's not forget, the top of the market for doctors involves getting your own practice. How long does it take to save the money, and have the name, for the practice to be that profitable?
There are a lot of people with law degrees that wish that, at 45, they made the money that anyone with a breath makes in SV when they are 22.
I have seen finance: You don't have a life when you work for a big hedge fund. Not even close.
And let's not forget, you don't have to live in San Francisco to get paid very well writing software. I have a 4 bedroom house that is worth about 200K. I work from home. It's not hard to amass major savings when you don't have a $5000/mo mortgage. And if I am sick of the place, I can spend a month working from Puerto Rico, or an island in Georgia, go to conferences in Europe. How many doctors can say that? How many lawyers? And I am no early googler: I have never made a dime in equity.
As far as people being boring: Different people have different ideas of boring. For instance, I find the classic "I work in software, but look at my unique outdoorsy activity" profiles that most of SV seems to follow to be very boring. Yes, you can enjoy your rock climbing, or your kayaking, or whatever else you do, but it's not something that is really any fun to hear about: People with different activities like that just get to vomit information onto the other. At the same time, many people find the things I do, like reading literature, history and philosophy, to be boring as hell. There's nothing wrong with that.
Also, in America, we hide the things that might make us interesting, different from the crowd. When instead of belonging, we try to fit in, we do what everyone else does. For someone to be really interesting, they have to be different. To be different is to take personal risks of being disliked, because what will make you interesting for one person will make you a weirdo to another. In my experience, the more you get to know about someone, the less boring they are, precisely because of all the little things that we couldn't see before, when all they were to us was a role at a company and some clothes.