I have a very, very old laptop with me. I don’t know the exact specs, but it has a single core celeron processor and 4GB of RAM. It’s an old little thing, maybe 15 years old.
I installed Debian on it with LXQT and it was chugging hard. I don’t expect it will run modern browsers anyways, so give me your best distros that can run on a potato and have a GUI.
So your HDD may be failing if debian is chugging at the desktop.
Try swapping it out with a cheap SSD.
Aside from Debian, you could experiment with the 32bit version of mint. https://www.linuxmint.com/
SSD is going to be the big performance boost here. Cheap now too.
15 year old laptop may not have sata, please make sure before you buy a ssd