On a personal computer, you are giving a whole lot of trust to anything you run un-sandboxed as your normal user - it will likely have access to your most interesting files, browser cookies, maybe saved passwords. XKCD covered it years back: https://xkcd.com/1200/
This brings up another drawback of deb/rpm packaging, though: you need root access to install anything. I'm not sure about Snap, but Flatpaks can be installed and used by an individual user.