Oh, that's some BS! I shouldn't be surprised that they removed the button and require some special task to bring it back. They just more and more act as though they hate their produc--err... customers.
I use the Enterprise SKU of Windows 11 and you can fortunately still use the Domain Join option with that. Comes without that advertisement crap as well. The only caveat is that you canโt really activate Enterprise legally without a subscription and KMS but there are ways to circumvent that issue ;)