For folks without significant generational wealth or hitting the startup jackpot, feeling rich <=> having lots of disposable income. Before we even talk about personal finances, here are some hurdles I could see:
1. TC numbers (hypothetically ~$400k as you quoted, which generally agrees with levels.fyi) are not real income. We know what happened to (tech) equity this year --- this (unfavorable) gap between grant price/share and vesting price/share has deflated a lot of the TC, much more so if the grant date happens to be right before the onslaught. (Personally I landed almost square in this territory due to a somewhat forced job switch but that's another can of worms I'm not opening today).
2. Whatever is left from that TC number, tax man takes ~40% of it period. Deductions are for most cases a rounding error.
3. TL;DR housing costs scales with salary over here too. Long version: The kind of housing that (transplanted) SWEs and their families would reasonably consider in SFBay has generally been priced (by "the market") right up to the limit of their income-derived affordability, most of which is calculated (by the underwriters) straight from SWE base salary, which we know is constrained by BigTech paybands (which propagates to startups too).
4. Okay, now an inevitable personal finances bullet point: Educated responsible adults as we are, a significant savings (incl. investments) rate surely sounds prudent eh? Say (temporary) goodbye to another xx% of whatever's left at this point.
5. Adding insult to injury, avocado toasts are now about 1.5x to 2x their price compared to early 2020. I feel compelled to add that this agrees with the larger trend of any kind of prepared food.
6. Elephant in the room: Kids.
-----
I can go on and on, but hopefully I am getting the point across. The "salary man" of today has not only his theoretically big TC "pie" shrink over time, but an increasingly larger slice of it becomes marked as non-disposable. Assuming reasonable (not necessarily optimal) personal finances management and maintaining a reasonably high QotL (nothing excessive), I don't see me or my similarly positioned peers feeling rich / upper-middle-class-y any time soon.