The real solution was mentioned up thread though: they are designing it to be used that way, but you have to use snaps or flatpaks. Not third party apt repositories which can overwrite system components in an infinite number of ways.
If the only option they have is an installer that runs as root, then the safest way to handle that would be to run it inside a docker container. Those companies should probably not be shipping installers on Linux unless they target very specific distributions and are working closely with them to ensure they don't break the upgrade process, otherwise it's going to cause issues.
Edit: here are the snaps and flatpaks and docker images I could find.
https://snapcraft.io/pycharm-professional
https://flathub.org/apps/details/org.mozilla.firefox
https://flathub.org/apps/details/org.chromium.Chromium
https://flathub.org/apps/details/com.visualstudio.code
https://flathub.org/apps/details/com.jetbrains.PyCharm-Profe...
https://flathub.org/apps/details/org.kicad.KiCad
https://flathub.org/apps/details/com.valvesoftware.Steam
https://github.com/xanderhendriks/docker-stm32cubeide
AFAIK, Solidworks and eM Client are not available on Linux, but if they were you would probably see them available in one of those forms.
https://www.rust-lang.org/tools/install: Curl an .sh
Steam: https://store.steampowered.com/about/: Download and install a .deb
Firefox: https://www.mozilla.org/en-US/firefox/all/#product-desktop-r... - Download a .tar.bz2
VsCode: https://code.visualstudio.com/download - Download a DEB
Pycharm https://www.jetbrains.com/pycharm/download/download-thanks.h... - download a .tar.gz2
Python - Install from source or use a 3rd party dep.
https://www.kicad.org/download/ubuntu/ - KiCad is the only exception that wants you to use an official package.\
Docker is a pain to use; it's a crutch used by web devs and Dev-ops for complex business stuff.