I was quite impressed, last year, with what you can now do in Germany using the standard DB app, which will let you plan and pay for multi-mode journeys. As an example here is a journey from a street address in Stuttgart to a rural location some distance from the city. The screenshot is from the DB website but the app gives similar information. It is quite capable of showing a journey with urban train, two regional/long distance trains and two buses, and giving one fare for the whole journey.
I used this to make several journeys, during a relatively brief stay. A couple of these journeys, to locations well outside town, in times gone by I might not have bothered attempting just because of the time involved in researching timetables manually - then trying to work out what the fare options were, worrying about how I would need to pay on the bus legs, and so on. They are the sort of journeys that someone with a car might always have made, but that a public transport user (visiting and unfamiliar with local systems), previously might not.
The significant aspects, which we are missing in the UK:
- I could easily plan the entire journey, using an app that I already had on my phone, and one that I could feel was reliable (because it's provided by the national rail operator, not some kind of third party service).
- I could buy the ticket, for the entire journey, in the app on my phone, really easily, and I could use that digital ticket for the entire journey
- Bus and train times are, generally, indicated
- Bus stops, even in rural areas, are easily identified, and generally have up to date timetable information posted at them - something that helps greatly with confidence when you arrive at an unfamiliar location and are waiting for a low-frequency bus. This is one pretty simple thing that is so often missing in the UK. It can lead to worry about pretty basic stuff, like am I actually at the bus stop going in the right direction for where I want to go, and is this actually a live bus stop.