Is these enhancements limited to the safari browser? What about 3rd party ios browsers like chrome and edge? Also why does these 3rd party browsers not have ext

Is these enhancements limited to the safari browser? What about 3rd party ios browsers like chrome and edge? Also why does these 3rd party browsers not have extensions like safari recently got? Is Apple locking all these features down so they are safari only or is it edge/chrome that haven't implemented these features yet?