>>/11753/
> P2P

While broadly correct the normal term used was direct connect or connect by IP, where it was offered separately often in RTS games. P2P particularly nowadays means more like how consoles handle multiplayer (i.e. badly). Technically you can connect by IP to dedicated servers as well avoiding the dev/publisher run master server list too since it's functionally just a public list people can stick their servers on.

As for whether it exists that, dedicated servers and even LAN options are on their way out now that AAA devs and publishers are adopting matchmaking systems and unlock systems because it's a lot harder for them to control XP gain, force microtransactions down people's throats and 'fight piracy' with a decentralised system like that. Even games like CS:GO that don't sell gameplay changing items have an incentive for this since the ranking system is used as a skinner-box of sorts to keep people interested by increasing their digital badgerank. You can partly blame console players for this since they actually actively dislike the classic PC system of community-run dedicated servers and much prefer just hitting search to play. After the shitshow that is this current generation most of the hardcore console community hopped to Steam and latterly similar walled gardens and ate this bullshit up.

> I would like to gather a collection of games that i could still play mutltiplayer with friends, even if servers close.

9/10 times if the game is older than ~5 years you can still connect manually to each other if the master server list is down. Just learn how to host a dedicated server (shit is really easy, usually the game has the files needed included), how to open ports/which ports need opened for the game in question (again really easy for anyone with an IQ above room temperature) and then pass your friends the IP. All they usually have to do then is open the console and type connect [IP]. In other cases community created alternative server lists are available usually along with a fanpatch. Part of the reason the current era of matchmaking is such cancer is they do becomes unavailable once the main servers are shut down but with old games it's generally a non-issue if you just want to play with friends. What dies, assuming no replacement community-run server, is the ability to play with random other users in a community.