I am a Firefox user for quite a long time. I think it is over ten years since I started using the fox browser (I know, I know, it is a bear-panda). I always valued its extensibility, addons (extensions) for so many things. Compared to other browsers Firefox was always the king of customizability. I am aware of its minor flaws (speed, memory footprint, startup time), but ability to customize it to my likings outweighs minor warts, at least for me.
Unfortunately the time of customizability is coming to an end. Mozilla is thrashing those thousands of addons, which were able to change virtually anything about the browser, just to limit Firefox to just some crippled addons like Chrome has. It is called WebExtensions and many great addons will not be available on it, because of severe limitations of this WebExtensions API.
I have fought for keeping the current system working together with WebExtensions, not only to keep all of my add-ons alive, but also because I believe a can-do-whatever-you-want extension system like exists today is the best quality Firefox has over other browsers. Unfortunately I’ve failed to convince them of this, as have they failed to convince me of the benefits they expect to achieve with a WebExtensions-only system.
I fully agree with this quote, Firefox is going away from its roots. Firstly it was the reworked (awful) GUI which reminded so much of Chrome. It was easily fixed by an addon like Classic Theme Restorer. Now Firefox is dropping also its advanced and almost unlimited addons API which is being replaced by something so restricted that it will not be possible to implement most of the best Firefox addons. Firefox is becoming a Chrome clone, only worse. It can’t compete with Chrome in speed and now only major advantage - addons - will be lost as well.
I am seriously considering leaving Firefox, after all those years (a decade), and probably switch to Chromium or maybe I will try Vivaldi. I feel betrayed by Mozilla and sad about downfall of Firefox, once the great king in customizability.