The speed of GCP's internal control panel isn't going to affect Google's bottom line like it would with their search offering or other massively user facing things. Google could redo this frontend from scratch and make it really lean and fast, but they clearly don't think they need to.
You might be surprised there... enough friction for the developer experience will open the door to opportunities for other tools/platforms to take root. If the AWS UI/UX was exceptional, there's no way Google or Azure could have gained the footholds they did.
