Valve has been using MoltenVK to run Dota2 on Mac1. I'm a bit worried that if Valve would cut the funding on MoltenVK2. Furthermore, CS:GO had been an example of a cross-platform example for multiple-player game. Valve's games may still support Linux/SteamOS, but what if other developers only release their games as win-only in future?
It’s sad that these games are not covered by PS+ deluxe. $120 sounds a bit expensive to me, but it depends on eager you want to play these old games.
Quick calculation: Assuming you have 5 games to play on PS3, you spend $120 for the console and $200 for the pre-owned discs, you’re spending $62 on average, which is almost the full price of a new release game. If you think these games are interesting enough, then this is a to-go decision.
As many people has pointed out, it’s always worth to try the simulator on PC first
As you stated, there are countless of great games you haven’t played. I think it is worth $100 unless you plan to buy a PS5/Xbox very soon.
You can try to find cheap pre-owned PS4 discs. Besides, you’d better have a look at PS Plus Extra Game list. Spending the price of 1.5 games, and you can enjoy 15+ games within one year.
For me I would not upgrade the monitor now. Only PS4 Pro support 4K gaming (for some games), I’d save the bucks for monitor upgrade in future.
KDE Connect: https://kdeconnect.kde.org/
I also use Resilio Sync. It’s not open source software, but it’s self-hosted https://www.resilio.com/
There are also open source sync services, like nextcloud or syncthing