If Firefox was a better funded and more competent alternative to Chrome we wouldn’t even have this whole Manifest v3 mess since Chrome would just lose all their users.
I don't think that's an issue of competency - which I understand as functionality/feature parity in this wording.
Chrome gained and became this popular likely entirely due to Marketing and big-corp ecosystem network effect through pushing it - through Google, Google Docs, and related Alphabet services.
I don't think Firefox was every really inferior. I've always preferred the dev tools and a few other things over Chrome. There was merely a time where performance was worse, but that likely only mattered in benchmarks - and marketing.
The field is incredibly broad. Choose a field or employer or project that's not doing that an you're fine.