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.
The question should be: “Where NOT to find movies to download in high quality in .mkv file format?”
Why!?
You will have an easier time finding quality media in .mkv than not, its one of, if not the most popular formats out there
various torrent sites.
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.
Lol
Look for “remux” – that’s the file direct from Bluray. If you need an invite to torrentleech DM me an email address to send it to.
Why mkv? Use a torrent site (with ublock, etc) or bring up a streaming site and use yt-dlp
Private trackers
Thats… like the right place