I don't recall my issues being media file or workload specific [0]. It was specifically just general frontend stuff I believe [1]. Although I should probably also mention that I don't remember much to begin with, other than my decidedly negative conclusion that made me switch players, and the overall personal narrative around that. It's been quite a few years if not a whole decade.

[0] Doesn't mean there weren't any, but then I was not doing anything special. Just watched anime, listened to music, streamed YouTube. Hardly an extraordinary workload for VLC, or indeed any media player in general.

[1] I remember them changing around the volume slider widget back and forth ad nauseam for example, and that becoming in some particular way defective that I cannot recall.