This is really a bad idea. I absolutely do not want to explain where I am going anytime I get on a bus or train. In Switzerland, most people just get on because they already have some general ticket for the year or month. And even those that don't, you can just enable 'EasyRide' and as long as that if active, at the end of the day (or when you disable it) it will calculate whatever you used.
And you don't need 'there'll be a pickup within X minutes' because regular bus stops in a developed country already tell you all the buses that will come when. Some like 'Line 1, 2 min', 'Line 9, 5min' and so on.
And for your end to end journey, you can simply open the app and look up your whole journey when you are planning it. If you really don't want to wait a few minutes, you can get there on time.
> but semi-automatic based on where those on the bus (and waiting at stops) are actually going right now.
That's a solved problem with 'request stop'. If its in a city, 99% of the time you stop anyway. For less populated routes, the bus driver can just stop if somebody request its. Its an incredibly simple system that has worked for 100+ years. In Switzerland we even do this for rural trains and it works just fine.
The data companies actually need is this, what bus routes are often full and when. And based on that they can increase frequency.
For example in my city, the main bus line is already really large buses (120+ people) that run every 10ish minutes. And during peak times they run a few extra to increase frequency to 5ish minutes.
In a city, you can run 15min frequency even on the routes that go into the rural area, and for anything else you can do more then every 15min. That fast enough that additional on demand pickup doesn't make much sense.
The most important point is, don't ask people for data just because you want data. If people want to use the app to look up end-to-end journey or buy tickets, that's something you can use. But I sure as shit don't want to open an app anytime I get into a bus, tram or train.