I liked being able to open a new tab and tab once over to the search bar (or click on the search bar if I'm done with my current one) then simply hit enter to get to my search engine of preference. I've been doing this for so long that it's like running a quick macro with my fingers; I don't even need to really think about it.

I just looked through about:config, searching for 'search', and didn't see anything there that suggested a quick reset back to usability.

I'd hate to have to download another extension (if anyone has even yet created one) just to get this functionality back.

I also noticed in firefox 128: I've noticed that you can no longer delete previous searches from the search field. Previously you could use the arrow keys to navigate, then press the shift or option key (varies by platform) in combination with Delete to remove old entries.