gaas - Games As a Service - games are live service, constantly updated multiplayer games that are usually f2p (but not always) but most importantly heavily emphasize paying constantly for battle passes, skins, cosmetics, mounts, pets, gacha loot boxes, pay to win potions/xp/levels/etc, on and on.
Its the most profitable area of gaming and involves everything from Fortnite, Call of Duty, Roblox, Genshin Impact, Overwatch, Diablo 4, 99% of mobile games, etc.
The biggest issue is most people are extremely comfortable with the 1-3 GAAS games they currently play and getting them into a new one is EXTREMELY hard. Everyone is chasing the next billion dollar a year Genshin/Fortnite but almost all of them fail - xDefiant, Concord, Suicide Squad, Foamstars, on and on. Big studios are throwing tons of money at it at the expense of AAA single player games which have been slashed a lot.
Most years we get 5-10 amazing AAA single player games, this year we've gotten like... 3 or 4? so a lot of people are salty at Sony, Microsoft, Ubisoft, etc wasting money on this shit especially when they infest it with characters who are all "put a black girl in it and make it gay"