Comment by xfp

Of h.264, h.265, vp8, vp9, and av1, h.264 is the only codec with consistent support across all of chat/messaging clients, browsers, smart TVs/phones, tablets, and streaming devices. The population of active, supported devices and software is much larger and much older than people realize. As such, it remains the only viable video codec if you don't want to be forced to provide multiple encodings.