Sounds like you picked the wrong distro!

I've put Linux on a few computers over summer. Actually, I put Debian on a few computers, but I tried a few different desktop environments. Debian internally works fine for my needs, and IMO it's kinda a "low drama" OS. So on my 4-year-old laptop and 7-year-old gaming PC, I used KDE Plasma, and on my 15-year-old PC I used LXQT, which is considered lightweight, after trying a number of options. The laptop has NVidia graphics and the 15-year-old PC has some janky GeForce integrated graphics, so I have gotten stuff to work with NVidia. Debian in particular has a really straightforward guide on the wiki on how to install graphics drivers.

I use Librewolf (Firefox derivative) on most of my Linux PCs, but Firefox ESR (extended support release, bundled with Debian by default) performed fine on the two newer computers. It's a bit sluggish on the older one, but fit for purpose.

I really think you should give it another try. Debian has live installs preconfigured with all the different desktop environments. That's how I picked Debian with KDE Plasma: I tried it out for three days and I decided i needed to have it.

There are probably compelling reasons to go with a distro other than Debian, but IMO Debian works great for me almost 100% of the time for a few different use cases. It's probably not the best OS for everyone, but I do think it's "pretty good" for most people. It'll get the job done.

But more importantly, there's a Linux distro for every niche. There are lots of lightweight distros with old PCs in mind that are much faster than even old versions of Windows. If your computer somehow can't deal with a desktop environment, a window manager like Fluxbox will work great.