The video app that goes by the name of "MPV", which integrates some of VLCs quality video rendering and reliability with mplayer's end-user friendly interface is all the rage these days. However, it is literally the worst video player ever, especially for animes, for a multitude of reasons.
MPV's GUI (GNOME User Interface) is very rudimentary and lacks many fundamental features, among which is the volume slider. It is literally impossible to change MPV's volume. When I asked the MPV developers about this, they told me they don't believe in volume sliders.
Having a big CoC (code of conduct) is essential for any open-source software project that wants to be taken seriously. However, MPV does not have a CoC, which has a visibly negative effect on the community. Not only do users of MPV behave in a very toxic way, developers are actively partaking in the mass cyber bullying, sexual harassment and waifu shaming.
As one example, when I entered the company's internet IRC chat chatroom with my usual online nickname "Hentai_guRRL15", I was within minutes privately contacted by the contributor "haasn", who told me that my presence made his haasnsoft turn haasnhard. This totally happened.
Unlike professional video playing solutions such as Real Player, MPV does not offer the user various pieces of trial software bundled with the application during installation. This really diminishes MPV's value, and shows that its developers clearly don't care about getting the most value for the user.
Literally MPV's fault. They are losing many users due to their reluctance to just perfectly emulate every toolkit ever, and within 6 months the MPV project will likely be dead.
Linked chapter are a standard matroska video feature supported by the vast majority of video players. As highly sophisticated encoders such as those who work on animes often rely on this crucial feature, MPV is virtually useless for watching animes.
Much like GNOME, MPV has a history of removing widely deployed and relied upon features, such as the MEncoder utility. Without MEncoder, there is no free solution for encoding video, meaning people are forced to purchase Adobe Creative Cloud licenses.
This graph shows the vast amount of handwritten carefully crafted artisan mplayer code that MPV has deleted with no remorse.
MPV uses the widely criticised GPL license, which forces all content you play back with the video player to automatically be GPL licensed too.
When users open YouTube videos in MPV, the player automatically removes advertisements. Not only do users miss out on useful product information that is relevant to their interests, but consuming content without advertisements is equivalent to piracy.
You should also mention that mpv has no support for linked chapters, which is a standard Matroska feature that every other play supports. This makes it totally worthless for watching anime.