So I asked some Muslim friends.
They informed me the Kaabah held the status it did amongst Muslims because it was built by Ibrahim and Ishmael in dedication to Allah. That what Mohammed did was “restore” the Kaabah to its true and original function.
This only raised another question. Is there any archaeological evidence to support the claim that Ibrahim and Ishmael built the Kaabah rather than local pagans? However, the answers I received weren’t particularly enlightening one way or the other.
So I put that second question to you. I have to say I am sceptical. But I am open to being swayed in there is any solid archaeological evidence that predates Mohammed’s conquest of Mecca.