I just installed apt cacher ng for catching my apt upgrade packages and saw a huge time improvement even though I have a good internet connection. It act as a proxy and caches the response packages.
Do you run something similar? Or maybe even run a local repo mirror? Warning, they are really big so I don’t think it is recommended unless you really need almost everything.
At the beginning of the COVID pandemic, I was attempting to mirror all of my favorite distro repos, just in case of societal collapse.
jigdothe entire repositories of your Debian’s favorite architectures for the win.