I agree. It's low cost flights which are primarily the issue. If they became more of a premium thing, people would regulate their use to when it was strictly necessary, as they did in the 1990s when they were available but much, much more expensive than now.
I suspect that a "flight" of morning flights leaving at 0730, arriving at a central airport - say Manchester - at 0810-0830, then another bank leaving 0850-0920, on small planes, would be sustainable, give
more journey options across the country for those who need it, would
integrate well with HS2, and would reduce in
less fuel used by domestic aviation.
You could have flights to/from
scilly/newquay, exeter, bristol, southampton, jersey/guensey, cardiff in the south
newcastle, glasgow, edinburgh, aberdeen, inverness, wick, various scottish islands in the north.
So you go Exeter-Inverness if you need it for a day trip. Or Exeter-Glasgow. Or Exeter-Jersey. Or Bristol-Aberdeen. Or Newquay-Aberdeen. Hell you could even to Newquay-Bristol.
A flat fare of say £300 each way, and a free transfer on HS2 from Manchester to Birmingham or London on HS2, which would allow a 2h30 trip from almost anywhere to anywhere.
During the day the planes could operate more flights to genuinely needy places - like Scottish islands, Channel islands, etc, then return for an evening bank of flights leaving about 1800, meaning a 2000 arrival.
I believe this is what used to happen in the BA days.
Ideally there would be some way of taxing people individually on flights, so that the tax you paid as part of the price increased exponentially based on how many flights you'd had in the last 12 months or whatever (I've no idea how that would work in practice, of course!)
Of course it wouldn't. That's a terrible idea. Someone generating useful economic activity being taxed more than someone going for a weekend ski trip?
Have a carbon tax for CO2 output. Use some of that income to distribute a "flight credit", say every person gets enough flight credits to pay for the typical CO2 cost for a yearly holiday to Cyprus and a weekend break to Rome. Those in areas of poor rail transport could be distributed more.
Those credits come as "money". If you take the train instead of flying, you pocket the credit.
All the benefits of a carbon tax (reduce unnecessary flying, encourage more economic planes) but without the "I can't have 2 weeks in benidorm" whines from the left.