Opera started as a paid browser and nearly went bankrupt. They even had ads on the free version. Barely anyone paid for it and the ads killed adoption.

Heck, even Netscape Navigator started out as shareware. It was "personal use only" but most commercial users never bought a license. It was eventually defeated by Microsoft Internet Explorer, which was free for commercial use even before it shipped with the OS.

If there is any chance someone will attempt a paid browser again, it will most definitely be based on Chromium (or maybe Firefox) rather than written from scratch and no website will make any effort to test on it (just like barely anyone ever tested on Opera).

If Jetbrains were to build a browser on top of firefox with a similar level of features to their IDE’s, I would absolutely pay for that.

Developer tools is already invaluable, but there’s no reason it cannot be better.

I care and would pay. Same with websites. especially if the experience was easy, scalable, and protected my privacy and anonymity.