buildx itself will not solve the exec format error. That error happens for example when you are using a binary on arm64 which was actually built for amd64. So you need to make sure that the container you are using has the right architecture (platform). If it doesn’t, you have to find out why.
Based on your other topic, I feel ther is a misunderstanding here
If you for example replaced your multiarch image with a single arch image on Docker Hub, you will get the wrong image with incompatible binaries.