You are absolutely allowed to use GPL software in commercial products, why are you deliberately lying or misleading?

GitHub could only exist because it was built on top of git, which is also GPL licensed. This is not the only example but should be the immediate one since nearly a vast majority of devs touch git on a daily basis.

Maybe stop listening to your legal team and actually think for a moment. GPL doesn't prevent commercialization, what it does is make sure everyone contributes to the same project equally. Shocker, corporations do not want to contribute to the common good they want to rat fuck it into submission for profit.

You have to then contribute all your changes back.

The Godot foundation picked MIT for a good reason. If your legal team says no GPL then no GPL. This has been standard practice for decades.