easyJet has traditionally had a policy of <4 hours over land, it doesn’t operate. EDI was perhaps border line but ABZ and BOH (ex LPL) are over that threshold be it by rail or road. Plus these routes are at a relatively low frequency, with relatively height capacity aircraft and in fact I think the LPL-BOH is only twice a week and explicitly targeted at the staycation market.
As other have said, airlines have to reduced cash burn and keep crews in check. Operating revenue generating flights is the optimal execution of that in the current circumstances.
EZY’s programme in general seems to have been parred back considerably, particularly when compared to FR. I’m not convinced that FR have been filling MAN-CHQ twice a week so banging on about environmental credentials is a bit ingenious.