To enable brightess control (Fn + right and left arrow on Acer) an entry in a grub file (assuming grub is used) needs to be edited. But files like that can't be modified without admin or root privileges.
Interestingly, I've never had that issue; and whilst I've pretty much stuck with Linux Mint ever since Ubuntu went all weird looking, I've run it on maybe 4 different laptops now (two Thinkpads, one of unknown manufacture that's actually my official work-supplied device, and one I can't recall now) and the brightness (and volume) buttons all worked out of the box. Obviously I can't speak for other distros. One of the two Thinkpads ended up with Linux Lite on it (because it was a feeble Celeron monstrosity), honestly can't recall if the brightness buttons ever worked with that - it was my "IMDB" box that I used when watching TV & wanted to look up an actor or somesuch.
WRT software - yeah, that is something which seems less polished than Windows. For the most part, installing stuff on windows (prior to v10 anyway) was pretty well painless. OK, getting it to actually function AFTER installation was sometimes "entertaining"; with Linux it seems the opposite is true: Sometimes it's a bear to get something installed; but once installed it usually functions just fine. Being a software dev who started in the era when windows was a DOS program, I'm comfortable just using apt on the command line. And when it comes to finding apps, I usually end up searching the Web for something to do what I want, and once I find it that's usually got the apt instructions (or alternatives. AppImage is pretty good, although I have found a couple of those which don't work properly).
Foolproof way of doing the testing is to use VM like Virtualbox - it's free and available for Windows, Mac and Linux. If one breaks the system inside VM (I've done that many times), it stays there, without affecting the host system.
Fun anecdote: about 10 years ago now, that's how I ran Windows in my day job: Linux PC running VMWare (VirtualBox didn't support USB back then) with the guest OS running Windows. I also used to have a couple of Linux VMs also running at the same time, because the client software we used was supplied as a Linux-based CD image. So... I'd basically "burn" one of the VMs with the CD Image & boot it up, which meant I didn't need to use any dedicated hardware. Except... one day, I somehow managed to burn the install to my main PC! Weirdly, Windows kept running OK for a while, but then things started to get a bit iffy, with random crashes and other glitching. So I rebooted everything and BANG! Byebye PC. Had to re-install everything from scratch. NOT ideal. Had I done the same thing to a Windows PC, of course, it would have spat the dummy instantly, instead of lulling me into a false sense of security by continuing to run for a while!