What do you think Firefox’ developer tools lack? I am a full-stack developer too, and use them without issues. Chrome has some tools/options that Firefox doesn’t; and viceversa; but 95% of what one usually needs are present in both; and served in a very similar way UX-wise, so I don’t see how one can consider them “not comparable”.
An anecdote: one of my colleagues that uses Chrome published (recently) a list “10 must-have extensions for chrome development”, and most of those were present natively in the firefox developer tools! (e.g., color picker).
I don’t know how long ago did you last try Firefox’ developer tools; if you didn’t recently (or used a standard version of Firefox) I suggest you try them in Firefox Nigthly (which is as stable as normal firefox for me), they introduced a lot of stuff recently, plus redesigned them in the latest version.