For me, the outdated packages in stable have actually gotten better over time, as DEs get closer to a place where I don't need any major updates to enjoy using them, Flatpaks become more readily available, and on a subjective level, I get less and less invested in current Linux news. Before Debian became my "forever distro", I'd hopped to it a few times, and often found myself wishing for a newer piece of software that wasn't in backports or flathub, or simply being bored with how stable it is, but that's been happening less and less. And I feel like Debian 12 in particular left me with software that I wouldn't mind being stuck with for two years.

I've gotten warnings to upgrade my browser with Debian's Firefox ESR, but they never affected a website's usability in a way that a newer version would fix, and they do provide security updates and new ESR series when they come out; even if you must have the newest Firefox, you can use the Flatpak.

Additionally, I'm currently on testing in order to get better support for my GPU, and each time I've tried to use it, it's worked for me for a longer time than the last as I get better at resolving or avoiding broken packages. If you do experience issues like the one you described, and can replicate them, and no one else has already reported them, you should report them to Debian's bug tracker. The whole point of Testing is to find and squash all the critical bugs before the next stable releases.