Some people have come up with the word "enshittification" to describe the basic cycle of modern web services.

The cycle consists of three parts:

1. You make the service that attracts new users by providing what they want. Often you do that at a loss, because your goal is to gain a big enough userbase for steps 2 and 3.
2. Once there's enough users, you shift to attracting commercial interests instead -- vendors if you're running a store, advertisers or celebrities or other "big clients" if you're a social network, etc.
3. Once both users and commercial interests are hooked, you can start tightening all the rules and switching completely to profiting yourself and your shareholders.

Oh BTW, the Cinny web client for Matrix does a very good job replicating the general layout of Discord without being an outright clone. There's even a feature to "Categorize Subspaces" that lets you precisely replicate the server/category/channel structure of Discord using Matrix spaces.

insert that clip of Michael Scott from the Office shouting various varieties of "No!" here

An unusual suggestion for you: BeamNG.Drive. I wouldn't call it a racing game per se, the actual "racing" part is kinda limited, but it's got very realistic driving and crash physics, several different environments to race in (both track-like and open-world-like) and lots of opportunity for screwing around and modding. It's a PC game, though, and requires a strong machine to pull off not just the graphics, but also the physics calculations.

If the discussions I see on Mastodon are anything to go by, then the moment people find out that your hypothetical future instance shows ads to its users, they will embargo you by blocking all communication with it.

And hiding that would be impossible: since Lemmy uses the AGPL license for its source code, when you add the advertisement code to it, you'll legally have to publish the changed source code, at which point people will be able to find out what exactly you did to it.

P.S.: also, the possibility of doing that (or even just collecting and selling data) is exactly why a lot of fediverse users distrust large instances like mastodon.social, to the point that these also get preemptively blocked (though also that one specifically is said to inadequately moderate the posts people put out, as the spam-bot incident has shown, so there's more than one reason to do so)

I used to slightly dislike GoL for putting up a lot of Google Stadia news just because, from a technical point of view, Stadia ran Linux, but otherwise it's a very decent website.

I think they're fun, but I am terrible at any kind of competitive play. I just occasionally hang out in FightCade to watch SSF2T matches.

Here are some popular choices:

• Xonotic, an arena FPS in the style of Quake 3 and Unreal Tournament that has a thriving online scene -- including non-standard modes like Defrag
• Hedgewars, an artillery game that's basically "Worms: Armageddon", but with some annoyances removed (like stray solid pixels get automatically removed, jumping is easier to do, etc.)
• Teeworlds, a fast-paced 2D multiplayer action game
• The Battle for Wesnoth, a turn-based strategy that (unusually for a PC title) adopts a gameplay structure more reminiscent of console TBSs (comparable to Advance Wars or Fire Emblem, but not a clone of either)
• Minetest, an attempt to make a Minecraft clone that has since turned into a very flexible engine for block-based games

And personal suggestions:

• Mindustry and shapez.io have already been mentioned by another person here, they're worth checking out
• Shattered Pixel Dungeon is a newbie-friendly roguelike
• speaking of roguelikes, NetHack is a classic, although not as user-friendly and way more difficult
• Simon Tatham's Puzzles, a collection of small games that all implement classic puzzles (Solo is sudoku, Pattern is "Japanese crosswords" aka Picross, etc.)
• LAN Master (video, download), a legit public-domain open-source homebrew NES game where your goal is to connect all computers into a network by rotating pieces -- obviously you'll need an NES emulator for that, FCEUX, Mesen, Mednafen, ares and Retroarch are good FOSS choices for that