Flixbus might have been the answer to the original question, depending on price on the day of course.
On Deutschlandticket, from German news the next federal-Land meeting mentioned by LNW-GW is on 06/11. That may not resolve the problem (in Germany everything seems to lead to another meeting, sometimes to decide the conditions for yet another meeting).
Numbers: currently 1.5bn, annual, from each of Bund and Länder, extra costs split between them. The operators association, VDV, say they need an extra 1bn in 2024. As fares go up 8% or so in January more people will switch so they suggest Dlt increases to 59 per month to avoid this.
Total subsidy of roughly 4bn annually divided by 13m users suggests it is not insoluble. Per current user that is 300 annually so 25 per month extra so price 59-75 per month could eliminate direct subsidy (usage would fall as some revert to cheaper local seasons).
Note that is only the Deutschlandticket direct subsidy. Overall public transport subsidy, regional transport is a Land not Bund problem but partly from central taxation, is a headache for yet another string of meetings.
Klimaticket, which gives all trains not just local but in a smaller country, works out about 91 per month so it looks as if the clever Austrians picked a sustainable price from the outset.