You can mod things on Linux, it’s just slightly more of a pain because you have to usually manually place files in the right locations, since the mod managers are kinda hit or miss on Linux.
That being said, I was recently able to mod Minecraft and Valheim pretty extensively with mod managers (I forget which one for Minecraft, but I used r2modman for Valheim which worked great), and I got the Mass Effect: Legendary Edition mod manager working enough via wine that I could mod that too.