I agree, a CVS was not essential for any of those operations, although it would have been useful to varying degrees (Libya pretty handy, Afghanistan not so much). And that is a problem that the RN tussles with but doesn't like to talk about.
However a flexible carrier, such as the QE class, would have, and will, provide an enormous amount to defence. From defence diplomacy to NEOs, MSO, counter piracy, counter drugs etc, a carrier with 12 JSF and a selection of rotary will be useful pretty much every day that it isn't alongside, and even then, arguably its existence can still provide an effect.
And then there is the Falklands / Sierra Leone scenario. The RN constantly intimate that the chances of land basing in future conflicts is unlikely and it must be irritating that they are constantly proved wrong - but at the end of the day land bases aren't assured and some situations will arise where a carrier is the only realistic option hence a need for the flexibility that a carrier provides, particularly one that can offer either a rotary / FJ mix or a larger (24) FJ capability.
In short I believe the RN do overstate the case for a carrier but, as an RAF officer who has worked with both Land and maritime, I believe that the carrier will offer an enormous capability and flexibility across defence and we should certainly be getting 2 in order to have a 365 day capability.
Just so long as the RAF provide most of the FJ pilots.
Don't confuse "top trumps, lots of FJs, looks good on the military channel" with the reality of defence today, and in particular what the RN has to offer.