levels.fyi does not say everyone makes $300k+ - it says people at specific companies in a specific region make that much. It makes that quite obvious from how you have to select the companies, the level, and then you see where those offers are geographically and with how much experience/tenure.
search for a city and see if it compares in any way to your salary?
People also disregard the infamous “4 year cliff”: At most of these companies, your initial stock offer fully vests in 4 years, so your 5th year, your take-home comp nose-dives. Even if you get modest raises and “refresh” stock grants (which not all companies do), you’re likely taking a huge hit in year 5. I’d be interested in a levels.fyi filtering out people’s first four years.
Even if they DID make you take a paycut you could jump ship every four years anyway, so why would you care about comp past year 4?
At Google, they're between 25 and 50%, depending on a lot of stuff. My initial grant was ~150k, my first refresher was ~40k, and it's a wash if my 4th year refresh will match my first year, that will likely come down to if I make L5 or not.
It probably does also vary with your role/responsibilities - I am a software engineer in SWE on high visibility/impact work. Apple does definitely does make you earn refreshes - they don't give them for average performance oftentimes is my understanding, there seems to be a lot of stories out there that this is the case.