Whether or not we have an autonomous organic manned Fleet Air Defence will make b*gg*r all difference to our credibility on the UNSC. Russia (hardly a minor power) did without it for decades, China has never had it. Italy and Spain, however, do have it.... so does India, and so does Brazil.
I would jettison the capability long term, if it was necessary to bolster more important capabilites, but that is not what is being proposed here.
Losing the SHar for the last six years of its career is just that. There is no proposal to jettison the CVS, or to take the GR9 off the boats. There is no proposal to cancel CVF or JSF, and there is no reason to propose that cancellation of SHar will make that more likely. Indeed, if you are correct, the brief absence of this capability will prove so limiting that there will be huge pressure to restore it.
In any event, it's about priorities. We cannot afford to do everything and the SHar is the 'least worst' FJ platform to withdraw.
Weighed up against arguments based on sentiment, tradition, and ill-defined "What if"s there are a host of compelling reasons why the early withdrawal of SHar represents the best option for UK plc.
It will provide the greatest savings.
It offers the least versatility and operational utility.
The capability it offers is least likely to be required in the timescale involved.
The capability it offers can be provided by land based assets or by allies.
Exercising the SHar's capability is problematic at the moment, because the carriers we have aren't big enough to embark a sufficient number to carry out their role.
The Cold War is over. The world has changed.
Like it or not our political masters and the chiefs of staff have decided that autonomous ops are not what we are structured or funded to undertake.