I haven't done a video call on it but it does work for youtube. It's best to pause a video at the start but it buffers and plays just fine. Blocky but certainly watchable.

Zoom works in 500kbps environments in my experience.

You won't be in crispy 720p or 1080p, but you can still talk to other people.

If the data speed is sufficient but they’re intentionally throttling video you could maybe get around it a VPN.