Removing some of the default shared folders can decrease CPU usage (e.g. remove /Volumes and /private).
Check storage with:
docker info |grep Storage
In case of performance problems you can run:
docker run --rm=true -it --privileged --pid=host \
<image name> /usr/bin/top
See disk space:
docker system df
Remove stopped containers, dangling images, the build cache, and unused networks:
docker system prune