NAB - the T45's were kept pretty busy from their introduction in service - long before the carriers appeared - that was all useful and necessary tasks no? They can't be doing the same, necessary, jobs now as a substantial percentage of the force is on carrier protection .
This is one of things that those who aren't carrier fans predicted - we don't have enough assets (T45's SSn', frigates) to do both properly. The carriers are a distraction in a small navy.