> matroska is a gigachad format that stores everything including all the DVD special features.
I also ignored .mkv for about ten or fifteen years, until all the rippers announced that they were going to standardize on it, which meant you could expect it to be fairly well-supported. If I end up transcoding or creating some kind of video, I still just use mp4 and h264/aac, because it will play everywhere on every device without any problems.