EDIT: I still don’t understand the general dislike towards Usenet in this community. Once I took the plunge, I honestly couldn’t dream of going back to torrents again. It’s just so damn convenient and reliable.
I think it’s a bit unfair too, buddy. Usenet with the *arr stack and Jellyfin is such a great experience with all that automation, once you’ve got it all setup. Mine’s setup to preference H265 and 5.1 channel audio, and specific resolution/quality. I mean, yeah you can access much the same content completely for free using torrents instead, but it feels like going back to the steam age now to do it all manually.
You can download in whatever format is available for any given movie. Often movies are available in multiple formats, especially the popular ones. DM your email address amd I can invite you to a private tracker but only if you promise to keep a good ratio.
Also I’m sure some other commenter is literally going to say “mkv is a container not a format” but whatever, if you want mkvs the movie or show you want has to have an mkv available.
MKV is just the container though, what really matter are the codecs and their parameters. Transforming the container (aka remuxing) doesn’t require a lot of processing power, and in fact some platforms like Plex will remux an MKV to another format on-the-fly to another container if the player doesn’t natively support MKV but otherwise support the codecs used inside with little effort required.