To clarify, you’re talking about manylinux wheels, yes?
In that case, you’ll need a manylinux version that defines libtbb as part of the platform, so that it doesn’t have to be bundled into the wheel itself. (Or you need an index other than PyPI so you can require libtbb to be installed by users and provide non-manylinux Linux wheels.)
Otherwise, the promise made by manylinux/auditwheel is that anything not considered part of the platform will be bundled. It’s not ideal, but it works better than any of the alternative ideas that have been considered (and people were willing to write the tools to make it work, which is a very important part of volunteer projects like ours).