When an app supports linux, it can do so by either:
- packaging it for popular distro repositories,
- giving instructions on how to build the app from the source code
or
- package it on distro-agnostic, package management solutions like flatpak or appImage.
These last ones are sandboxed environments. That means they have their own dependencies isolated from your system, so they dont have to deal with every distros pecularities at the cost of using more storage space. This is very useful for developers and in your case benefitial for the user because you can have both steam and zoom via flatpak on mint, arch or any obscure distro that has flatpak available, without any major problems.
Edit: Formatting
For the moto E4, Motorola has a guide in their support site to unlock the bootloader. I used it to be able to flash a 64bit rom for my moto g4 plus and the process was pretty straightfoward, although you do need a pc to use the adb command line tool.