Public financing of the press, newspapers stopping being garbage and selling subscriptions like they have always done, pay per article (cents), donations. Just some ideas of economically viable alternatives. There are good niche newspapers which survive with such models, it’s not like I am making it up.
I would say the opposite: advertising alone is not sustainable for the press because it creates wrong incentives (grab attention, clicks). This is why 90% of newspapers have the same garbage, short, generic articles. This is why you get rage baits, fake news etc. too, to some extent. So yes, you get websites online, but you get no information…