It's funny, more than any productivity app (though I do have a few of those), the Directory Opus [1] Explorer replacement is one of the things that I've yet to find a viable replacement for on both Linux and macOS. Unparalleled customisability, scriptable actions, outstanding performance (thumbnailing 10,000 images in a folder never causes slowdown), incredible search and "huh, why doesn't anyone else do this" features everywhere. I use my file explorer a lot so the friction is felt daily.

I'm using Forklift [2] on my mac at work, but it's a pale imitation of what a file explorer can truly be. I did some searching for Linux but it's all pretty pedestrian.

[1]: https://www.gpsoft.com.au/ [2]: https://binarynights.com/