But unbelievably ergonomic. A decade ago I rented one to do a week's touring (in France and Switzerland). On a standard bike the first two days of such outings were invariably spoiled by sore butt and shoulders. On the recumbent I knocked off 80km on the first day with not the slightest ache. A total revelation.
Recumbent bikes can promote over flexion of the neck, sometimes. Your neck isn’t neutral, it’s bending forward slightly, like tech neck. That’s not to say a recumbent isn’t ergonomic on the whole, but there are trade offs.