Why have we wasted £billions to introduce a tanker we didn't need yet
OAP: let it go. We most certainly did/do need a new tanker. The VC10s were past it and the Trishaw were pretty close behind. We might have got another 5 years out of them, maybe, but we still needed a replacement and your beloved Trijet couldn't fill the requirement!
more £billions for two giant war canoes that will not actually do what we need (in 6 years' time!)
Regardless of whether we need them now or in 6 years, there is a physical reality here: it takes years to design, build, conduct training and complete sea trials. The carriers, whether or not you believe in the requirement, will be worked up and ready to accept their aircraft when (if) JSF ever arrives.
Can't disagree with your last point though: the RN have mortgaged their future on 2 very big shiny new toys; whilst the RAF have mortgaged their future on a (wrong-type of) 5th gen fighter/bomber.