Having had the dubious pleasure of trying to use Meet from various Apple devices, Meet didn’t lag because Meet couldn’t produce video at all. Maybe I only operate at the wrong edge of the Meet ecosystem, but it did not compare well to anything else out there.

(I’ve tried Safari, I’ve tried the native app, and I’ve even tried the phone bridge (!).)

Achtually its AV1 which is even worse. but saves a bunch of bandwidth

As a result of a flaw in the protocol itself or in its implementation?

The implementation is what I was thinking of. I've also heard claims that VP9 is inherently slower to encode than H.264, but no idea if that's accurate. AVC/H.264 has very broad hardware support. For example, the 2019 MBP I'm using right now can't do hardware-accelerated VP9 encoding, but even 2011-ish MBPs can do H.264 acceleration in both directions. Intel's support matrix: https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video

For PCs with dedicated GPUs, Nvidia's matrix doesn't even mention VP8/9 encoding, and for decode there are a lot of VP8/9 "no"s for GPUs that have "yes" for H.264: https://developer.nvidia.com/video-encode-and-decode-gpu-sup...

AV1 looks like it's getting broader support, but it's still new. Zoom's release notes mention they'll use AV1 if the participants support it, and I don't see a similar note about VP8/9.

there are very few CPUs supporting AV1 hw encoding now, all is on the CPU

It's only in newer chips, but it's broader than VP8/9 was. Intel and Nvidia's newest chips support hardware en/decoding of AV1, while Nvidia never supported VP8/9.