Top brass seem not to be that interested in their low end aircraft; I understand the USAF wasn't particularly thrilled at having an A-10 until the US Army said it would make one itself. When it came along, it was treated with disdain in the USAF, despite its success in combat.
The CAS mission no longer has a dedicated aircraft in the UK. The Harrier did superbly in CAS in Afghanistan from what I heard. F-35 or Typhoon seems overkill in such a scenario. From what I read, including parliamentary debates, there was no real need to replace Harrier in that theatre. There were suggestions that the Harrier was being 'killed off', similar to rumours now about the A-10 in the USAF.
Was the Harrier unfairly assassinated? Would we use an F-35 to do the type of job Harrier did in Afghanistan? No, I suspect.
Would a pairing of F-35 with Harrier have been worth it? Both those aircraft could operate off the carriers and give greater flexibility in CAS role.