The thing is though both Meet and Teams use centralised server architectures (SFUs: Selective Forwarding Units for Google, "Transport Routers" for Teams), so your quality issues likely come down to network routing rather than the platforms themselves. The progressive quality degradation you're describing on Meet sounds like adaptive bitrate doing its job when your connection to Google's servers is struggling.
The reason Teams might work better for you is probably just dumb luck with how your ISP routes to Microsoft's network versus Google's. For me in Sweden, it's the opposite ... Teams routes my media through relays in France, which adds enough latency that people constantly interrupt each other accidentally. It's maddening. Meanwhile, Meet's routing has been flawless.
But even if Teams works for your particular network setup, let's not pretend it's a good piece of software. Teams is an absolute resource hog that treats my CPU like a space heater and my RAM like an all-you-can-eat buffet. The interface is cluttered rubbish, it takes ages to start up, and the only reason anyone tolerates it is because Microsoft bundled it with Office 365.
Your mileage definitely varies... sounds like you've got routing that favours Microsoft's infrastructure. Lucky you, I suppose, but that doesn't make Teams any less dogwater for those of us stuck with their poorly-placed European relays.
Since Teams is using the very old H264 codec and Meet is using VP8 or VP9 depending on the context, it's possible you also had some other issues with bad decoding (usually done in software, but occasionally by the hardware).
Overall, it shouldn't be representative of the experience on Meet that I've seen, even from all the bug reports I've read.