Doubt it these days at 40 yo, but in his prime I could absolutely see GSP come in that fight with the right gameplan, like he did so often when facing better strikers, and nullify Adesanya's striking with a grappling/wrestling clinic. GSP always fought his opponents where they were the weakest by dictating where the fight occured.
I think a 30yo GSP, pre ACL injury, would cause problems to Adesanya. He was a more well-rounded fighter than Adesanya is now, and he had the best wrestling and takedowns in the UFC in his prime. People tend to forget how good he was
I don't see Adesanya beating that version of GSP: