Is buildx for supporting multiple architecture? Do I need it on the parent image?

General Discussions
1

I’ve tried the buildx command explained in the documentation (from my Intel-based Mac):

docker buildx build --platform linux/amd64,linux/arm64 -t knetminer/knetminer -f docker/Dockerfile --push .

However, when I try the published image on an ARM64, I still get the usual:
standard_init_linux.go:211: exec user process caused “exec format error”

Is buildx enough to obtain multiple-architecture images? Or do I need more (eg, Linux images that actually support ARM)?

My image is based on another one, which is based on a Tomcat
+Linux image. Do I need to re-run buildx on all the parents?

Thanks in advance.