Multilib + the slackbuild script. Slackpkg+ and alienbob's repos make it super easy to keep a multilib system up to date. Slackbuilds.org is the first place I look if I want to install something new.
I do use flatpak for ultimaker cura, but mainly because there's no slackbuild and so many python deps.
If you run any proprietary software connected to the internet then it can send this info to whomever. If you use a regular web browser with Javascript enabled then a lot of this info can also be obtained by whatever website you're visiting.
For real. As privacy-oriented as most people on Lemmy seem to be, a good chunk of them would still freely give any of that info in a heartbeat if it would make Gaben happy or make Linux more commercialized.
The fact we are given a choice is a big thing for me. I hate when my info is just pulled from me without my agency. But I am happy to share info with open source project to help them improve. Also valve being a private company they can just build software as their main goal vs just making the line go up by any means possible like a public company.