Why has support for a large number of phones been stopped?

No, it’s 45/58 …

58 are released 2021 and newer, not newer than 2021 (that would be 25 released 2022 and newer).

2023: 4
2022: 11
2021: 30

Sum: 45

(Selecting multiple “Year released” doesn’t work in the selector, if you used this to count, but that should be pretty obvious from the results.)