It’s not companies that are the problem. It’s your friends, the type that always clicks on accept all and allow. Do you have any idea how many spam calls I get because someone allowed some proprietary app access to their contacts? And I have at least five friends who would enable recall without giving it a second thought.
I would recommend looking at this site. My personal recommendation would be simplex chat. It’s decentralized, doesn’t require a phone number and supports forward secrecy.
Snap does theoretically support other stores, but the code for the canonical store is proprietary so you’d have to reverse engineer a snap store and hope that canonical doesn’t break it with an update. Also apart from Ubuntu nobody uses snaps so why would anyone make a snap store? Btw they have improved snaps with faster start times and such, so they aren’t that much slower than packages or flatpak.
I have used a lot of different distros and I never had dependency problems whether on Linux mint, Debian, open suse or fedora. And yes, this can be a problem, especially on distros like Manjaro, but you still can use flatpaks/appimages/snaps and don’t deal with dependencies at all. NixOS and all rolling release distros can be great but they are not meant for people who are not ready to troubleshoot their system at any time. If you stick with a more stable distro like Debian you will most likely get a more reliable system then with windows.
I don’t have nay extension installed that interacts with containers. In settings I enabled container tabs under general and if I right click on the new tab button I can open a container tab, so it appears to be built in. I can also create custom containers for example I have one for google services. So if I understand you correctly the extension doesn’t do anything else special?
Originally there was KHTML, developed by KDE for the konquerer browser. This was then forked by Apple to WebKit which is used by safari and gnome web. Google then forked WebKit to blink, the browser engine chromium uses.