I have an older laptop that I ran Firefox on for many years.  At some point Firefox just got too slow, so I installed PaleMoon (a fork of the Firefox code that's lighter weight and faster) and used it for a few more years.  Then I started having problems with PaleMoon, so I installed Opera, and have been using it with no problems for the last couple of years.

On my main gaming machine I still use PaleMoon, but have Opera installed and use it occasionally.

Yes, modern browsers (all browsers really except those that aren't updated) rely more and more on hardware acceleration. This must be provided by the GPU (graphics card) driver. I recently had the problem that Youtube didn't work in some browsers, because my graphics driver didn't provide adequate hardware acceleration.

I tried to install a newer driver, but they all failed installing. This was on Windows 7. I didn't care too much about this machine so I decided to try the free upgrade to Windows 10. It worked and solved my driver problems. Most browsers provide troubleshooting info so that way I knew the problem was driver related. In most cases a reinstall or upgrade of GPU driver should solve video problems in browsers.

In Firefox menu bar click Help then Troubleshooting Information. It will open a new tab with info. There is a section called Graphics. You may find error messages in that section. If so that would likely be caused by the GPU driver not being good enough.

The newest version of Firefox has very detailed Graphics info so I guess hardware acceleration plays a bigger and bigger role.

You mention Firefox is a mess and if that's the case you should try starting it with add-ons disabled. Menu Bar > Help > Restart with Add-ons disabled

The reason some browsers may work fine despite faulty (less than ideal) GPU driver is that they have  fallback options such as using the CPU if GPU hardware acceleration is unavailable.

Despite my GPU driver being faulty according to Firefox, Firefox did still work on Youtube. It was my preferred browser Pale Moon that for some reason didn't fallback to CPU rendering when GPU acceleration didn't work.

Worth to mention is that I had no other issues whatsoever. Pale Moon didn't work on Youtube and the driver was marked as non-working in both Firefox and Pale Moon, that was it.

Since I've used Firefox since version 3 and Pale Moon since Firefox switched to Australis UI (Firefox 29), I don't feel like using another browser even if that means Windows 10 instead of Windows 7. Chrome lacks the UI customization I'm used to so I only use it as a reference for bad sites that don't conform to web standards, but Chrome standards. Thankfully very few sites are Chrome only.

Unfortunately your picture isn't visible. Firefox and WB don't play nicely together I've heard so that could explain Firefox UI problems.

Leave Firefox alone...it's a classic for having issues....and while you are at it Skype has a mem leak and [on mine] needs to be killed [end process] and restarted every day or three [I do leave my machine on 24/7 so it's not getting a kill on shutdowns].

Most [but not all] browsing is on Chrome which needs to be killed every few months too...

There is a brand new version of Firefox with a completely new engine, exactly like Opera's browser. I have both of those. Check it out it works great. Opera is a little better had more time to develop it Than Firefox's new version.

I've had very similar issues as Barb's. I'm trying Slimjet right now and it is a lot better! Thanks for that info. CCleaner doesn't see Slimjet however so I'm cleaning the history manually.

I probably make and view more videos than anybody ( Dreams ) and

I have No problem with Chrome all works fine for me Facebook included

only use Chrome

I don't use flash anymore, just html 5.

This is the best fix I have.

Lets say you use firefox and it isn't working right any more.

This is why, it has corrupted files.

If the usual emptying of all cached history data doesn't work you

could try this.

Delete everything in this folder C:\Users\you\AppData\Local\Mozilla\Firefox\Profiles\ .default\cache2\entries

If that doen't work,

First uninstall the program but that won't fix it.

Next you have to make visible all hidden files and folders in folder options.

C:\Users\you\AppData is the location where the corrupted files should be.

There should be 3 folders in AppData and you will have to look in each one

for firefox files and folders and delete them.Also look in common folders

in AppData and the program files folder and delete firefox out of there also.

If you are sure you have deleted everything then reinstall firefox.

You could totally delete firefox and install a different browser other

than firefox and use it for a few months or until it stops working and

then get rid of it as described above.

Now do a fresh install of firefox and it should work again.

You could try Brave browser and Vivaldi browser or maybe Linux.