

There’s nothing wrong with Mint, it’s solid. If it works for you don’t stress about it
The only thing is that it’s based on Ubuntu LTS so it’s packages can be a bit old. Doesn’t really matter much unless you have very new hardware and need the hardware support. Then something Fedora based like Bazzite would be better.
For getting newer software you can use flatpak/Flathub.
Bazzite is also “immutable” which makes it harder to break on a system level, but also harder to tinker on a system level. Mint is a “normal” distribution in that regard. Mint does have Timeshift for taking system level snapshots, on the off chance that an update or your tinkering breaks something. Its worth checking that Timeshift is set up for automatic snapshots




For jpg’s, no they will not get smaller. Maybe even a smidge bigger if you zip them. Usually not enough to make a practical difference.
Zip does generic lossless compression, meaning it can be extracted for a bit-perfect copy of the original. Very simplified it works by finding patterns repeating and replacing a long pattern with a short key, and storing an index to replace the keys with the original pattern on extraction.
Jpg’s use lossy compression, meaning some detail is lost and can never be reproduced. Jpg is highly optimized to only drop details that don’t matter much for human perception of the image.
Since jpg is already compressed, there will not be any repeating patterns (duplicate information) for the zip algorithm to find.