Same experience here! The only problem I have is that the Android search bar seems to ignore the default Browser setting, but avoiding it (opening FF rather than using the search bar widget) is a small price to pay for avoiding ads so effectively.
You can use the launcher too. If you set the launcher to open a new tab, it'll bring the keyboard up too. This means you're one tap from searching your query in the browser.
If you have a good keyboard, you can even use DDG !bang syntax. I find this very helpful for finding what I want fast.
Another option you have is to put the firefox search widget above you google search widget in your home screen. It's a bit ridiculous that the Google search bar can't be removed, but this is second best.
I did remove the Google search bar from all my phones. An old and defunct Samsung Galaxy S2, a Sony Xperia X Compact (Android 8) and a Samsung A40 (Android 11).
Which phone / OS do you use?
Btw, to search for something I open Firefox and type in the URL bar.
