Yes, you also have to keep the rural population in mind, but you simply cannot establish a regularly operating bus line to every single village. You have to focus on the (small) cities. And there you should offer not a cheap rubbish ticket, but a relatively affordable ticket to make public transport more attractive. Because, for example, using all public transport in a metropolitan area for 49€ per month instead of paying over 100€ per month is reasonable. This way you also get more people from the outskirts of Berlin, Hamburg, Cologne, etc. to use the train. Then of course you have to expand the routes and operate more trains. And yes, the rural population has decided to move to the village themselves. This does not mean a village with 5,000 inhabitants, but one with only a few hundred inhabitants. It was known before making the decision that you rely heavily on individual transport there. Everything has its advantages and disadvantages. Low purchase prices, longer commuting distances and higher costs, or vice versa. You just have to take that into account. In many small towns with 5,000 inhabitants, there are already mostly very regular bus lines to the train station, so you can get to the city quickly (30 minutes). But sending a bus to every small village unfortunately does not work.