WEBF,
Where are you expecting this task group to operate?
If it’s in the Pacific then yes, history tells us that carriers are practically essential, hence my earlier reference to American and Chinese strategic requirements. But the UK has no vital strategic interest in the Pacific that justifies the investment.
If it’s a NATO Art V scenario in Europe then I’d like to know where this task force is going to be employed. If the North Sea, Baltic or Mediterranean then there are airbases all around. If it’s the North Cape then there are some useful airbases, and if Northern Norway has been overrun then a) there are probably other priorities and b) it’s an obvious place to prioritise one or more of the US carriers to; it’s an Alliance effort and NATO is pushing a ‘Smart procurement’ agenda of avoiding unnecessary duplication. If it’s out in the open Atlantic then attacking aircraft have to run the gauntlet of fighters based in Norway, Iceland and the UK, plus the air defences of any screening surface vessels before they get into range. And there will probably be another American carrier out there somewhere too.
If it’s the Gulf then I would point to dozens of airfields and Patriot batteries...
There is also the slight problem that anti-ship missiles got longer in range while our fighters were getting slower. The timelines were already challenging in the days of Phoenix-armed Tomcats. F-35B is slower and has a shorter stick in AMRAAM. If your opponent starts to field low-observable aircraft, what had previously been a challenging timeline suddenly becomes impossible as the detection range shrinks. The carrier would need to be positioned up-threat (interesting...) and could be sidestepped.
But all this is beside the point. The decline of the high-speed interceptor and the rise of the close-in weapon system (in various forms) show that the game changed on this topic a couple of decades ago. Air defence of task groups rarely used to be pushed as one of the things we sought the carrier for. Why the particular interest now?