A lot of incorrect information about Firefox in this post thread.
From your post it appears you were using the Adblock Plus extension in Firefox prior to the Firefox update. You said it was disabled after the update. Adblock Plus is an extension designed to block ads on websites. An extension is from a third party developer, not from Firefox/Mozilla. If it is disabled ads won't be blocked. Go into Tools/Addons and Themes and re enable it and your ads should once again be blocked.
Oh, BTW, you mentioned Firefox is running in safe mode. Of course Firefox would disable extensions like Adblock Plus in safe mode. Run Firefox in normal mode and your Adblock Plus extension should work.
Vivaldi is another web browser. Firefox, Google Chrome, Safari, Edge etc are all software programs that are in the category of "web browsers". Vivaldi was created by former Opera developers. Opera is another web browser.
Firefox is NOT garbage. Its one of the best web browsers out right now and has been for years. Firefox respects user privacy and security, uses far less system resources, and is far more stable than many other web browsers especially when compared with web browsers from companies like Microsoft and Google.
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