The Armv8 Neon codec excels at 1080p and 4K H.264. For 4K H.265, only flagship chips work smoothly. For Exynos 850, software fallback still occurs.
MX Player has gone through several lifecycles. It started as a purely independent project, was acquired by Times Internet, and later pivoted toward OTT (streaming) content. Version sits in a sweet spot of history—released around late 2018 to early 2019. It represents the last generation of MX Player before the UI became heavily commercialized with movies and TV shows.