Uss Enterprise during Cuban missile crisis carried a wing of strategic bombers. Also, it wasn't considered something primary by Soviets, ballistic missile and SAC bombers were.
This carrier role is mostly outdated(french keep it barely alive to some degree, of course). It was growing outdated right then, in fact, with shift to Polaris fleet.
Also, being blunt, UK economy is incapable of 6-carrier navy with such airwing.
Deterrent against whom?
You need to grow back global empire to do gunboat diplomacy, as to deter someone against relevant action x.
Otherwise it'll look like QE in SCS again: rather pitiful, yet expensive geopolitical show. About as relevant as Italian performances on China station in 1930s.
None are direct UK threats.
The closest one, Russia, isn't a naval threat, and carriers can have any primary relevance against Russia(i.e. when they're more impactful than other means) only when it has a navy. In modern era, it doesn't.
Massive UK investment into a stretched surface fleet is basically the best scenario for Russia...
China is a bit far away, and is a bit stronger.
DPRK is further still, and again, it just doesn't care about UK carrier power, 1 carrier or 16. They already live with hostile air force right over the border, twice the size of RAF.
Like, look at what you're doing. The only two entities you can negatively affect with 6-6 navy (funny historical parallels) is US and EU. Girls scandal isn't a big enough fallout to burn Washington just yet.