Images are not optimized either. Plenty of folks with 10mb PFPs around here.
Unlike centralized social media your videos aren't automatically optimized on Nostr. Her are some good tools to compress your videos for smaller size and better streaming before upload.
🔹Android
FFshare - Open source, ffmpeg based
https://github.com/caydey/ffshare
Proton - Google Play Store
https://play.google.com/store/apps/details?id=com.arthur.hritik.proton.video.compressor
🔹Desktop - both are available for Linux, Mac & Windows.
Handbrake
FFmpeg
Discussion
This. When I vibed a game using avatars as game assets the biggest hurdle was optimizing them for use in game. Centralized services doing all the work for you has left most people ignorant of the importance of media optimization for Internet use unfortunately.