This is part of Googles strategy. Ever since the Chromium engine took off enough and everyone else fell behind they began introducing more and more changes that merely benefits them, with less public debate or proper communication (or even adherence to common standards). Last thing I remember, aside of manifest v3, was them killing off JPEG XL as it was a competitor to webp and webm (which they control). JPEG XL was actively worked on and would've probably turned out better before they killed it without any previous notice.
Given Googles dominant market position, their influence and everyone wanting to cut corners wherever possible sometimes Firefox support is just ignored.
tl;dr It's not Firefox' fault. It's Google's sabotage.
Do you vote separately for your president in the US?
In Germany we vote for Parliament, whoever receives a majority of votes then gets the governmental mandate and their candidate becomes chancellor. Many people thought there never would be any other chancellor than from either the "social" democrats (SPD) or "christian" conservatives (CDU/CSU, also just called "Union"), until 2021 when the Green Party got so good in surveys we suddenly had three official candidates.
I do know about the "electorial college" nonsense, just asking what exactly the votes are aimed to be for, government or specifically the president.