Like what other people mentioned in this thread about prioritization.
It's not hard to justify focusing on the most popular browser (which "so just happens" to be Chrome) over a browser that is less popular and not even a system default on Windows or MacOS.
Devs write bad code, gets fixed only in Chrome. Or devs test only in Chrome from the start because they don't have time to test everywhere and if it doesn't even work in Chrome you get bad looks, so it only works well in Chrome.
It's not hard to justify focusing on the most popular browser (which "so just happens" to be Chrome) over a browser that is less popular and not even a system default on Windows or MacOS.
Devs write bad code, gets fixed only in Chrome. Or devs test only in Chrome from the start because they don't have time to test everywhere and if it doesn't even work in Chrome you get bad looks, so it only works well in Chrome.