Yes, the version in the standard Arch repos won't play any mpeg2 videos. I have all the plugins installed so that's not the issue. I ran it in Konsole and it threw some error about VDPAU. I'm using an AMD card so I don't see why that would matter anyway. The VLC flatpak plays it fine but I have other issues with the flatpak. I'm using an RX 9070 XT.

Edit: Worth mentioning I didn't try playing mpeg2 videos in this weird git version after I saw this UI. I doubt it would fix it anyway.