here's an answer from one of the guys from the devteam

https://www.istartips.com/ru/google-chrome-helper.html

His google chrome helper process is eating GPU
This process, as far as I understand, is needed by Macs for faster chrome work
And for many, he eats a lot of resources
Mac OS and chrome do not worry at all and if there are extra resources they will devour you without problems
Even if he has one tab open, he may have extensions that mine or otherwise load the GPU
Yes, some of the renderings in modern browsers use the GPU, but this is only at the time of rendering, that is, during loading or switching between tabs, the time does not exceed a couple of seconds

And so most likely one of his extensions is eating GPU