What’s an alternative to explorer?

Unfortunately, just switch to Linux is not an option.

You can prevent recall from running and collecting data, you just can't remove it entirely without breaking some features. I don't think you can replace the file explorer, it's your desktop n stuff as well as file exploring, but preventing recall from running might be your best bet. Or, alternatively, if you don't use the features that you lose in file explorer by removing recall then you might be fine just removing recall and continuing on.