Firefox is my main browser. Anyway, it is unable to access sevreal websites. And for that reason, I need another browser (generally Edge) to access these websites. Example, the post office website in France. This website offers the ability to send paper letters online, they print it and send it. In the process of sending the letter, the website offers a preview of the letter. This does not work when using Firefox. It works when using Edge.
Another frequent problems is embedded videos. In many website, they do not start. And as well, the Google video conferencing does not work properly with firefox.
I would be happy to use Firefox for all purposes, but obviously, it's not possible. Probably websites authors do not test their site with firefox, just because most users use the same html engine (Google's one) regardless the brand of the browser. Unfortunately, this means that Forefox must be totally compatible with this html engine.
I feel your pain. If I want to go to icloud.com in Firefox, I have to wait about a minute and a half for the home page to come up. It comes up with a blank white page with "iCloud" in small print in the upper corner and then just sits there. The home page finally comes up and it behaves normally after that. If I go to Edge, it comes up like you would expect a normal website to, in like a second or two.
I am in the same situation. Firevox has been my main browser for more than a decade but now I find several things are inaccessible.
First example: On a internet buying site there was an inabiity to finalise payment. I went to Chrome and the problem went away.
Second example: On the official French government website for my retirement benefit there are several downloads offered. Firefox does not work for this so I now go to Chrome and the problem vanishes.
Third example : On the website of the British newspaper The Guardian, there are several comment sections opened for some articles. All worked well until last week when the comments section were not attached to the articles if using Firefox. I now use Chrome and the problem vanishes.
All in all my decades of fidelity to Fitefow are being severely tested and I am now at the point of going to Chrome permanently