It's hard to hire remote employees in different COL areas without opening yourself up to legal liability, if people are able to bounce around and hold onto COL salaries disproportionate to the local area.
Ex, if a bunch of white and asian bay area employees relocate to Florida, taking their salaries, and then Facebook hires some local hispanic employees at 1/2 the rate... well, you can try to explain exactly what happened after you get sued, but that doesn't sound like a lot of fun. And even if you legally get away with it, you are going to have a lot of REALLY unhappy employees.
Not to mention you're opening yourself up to a real game, where employees move to the Bay Area for a year to get hired at a high salary, and then immediately leave for 2x the salary. All you've done is turned salaries into a game that benefit highly-mobile employees.
So I definitely understand why this feels shitty, but I honestly can't see it working any other way for large corporations. You have to have some kind of local salary adjustment you can stand behind, when you're remote-first hiring.