I agree, proper bike infrastructure is painfully undervalued, even amongst transit stans

They are a major part of the future in medium-density areas. Less so in high-density areas, where individual vehicles of any kind create too much traffic to be a majority solution. Just look at pictures from Chinese cities in the 1980s to see how dystopian the combination of bikes and high density can be.

This assumes that the people are living far away from the railway, which is obviously the opposite situation in much of Europe and Asia.

France and Germany have been expanding local tram & Stadtbahn networks, even opening new ones since the ~1990s. Tram-Trains have also become popular in Germany, due to offering more stops in the middle.

Not sure if you mean trams or branch lines by local railways, but at least Germany has also been keen on reactivating old branch lines, often to resounding success and exceeding expectations (and few failures, although there are many hurdles that reactivation projects much pass to avoid that fate). S-Bahn networks with many infill stops are also popular.

Many S-Bahn stops also rely on walking for the last mile, which works well. There are also of-course people that come by bus or bike, but both seem like a smaller portion to me. There are efforts to try to get more bike&ride traffic to expand the station reach, but it's doesn't seem to me like it has increased a huge amount. There are also always efforts to expand park&ride, but the share of passengers using it is tiny [1]. The portion of people using E-Scooters and taking them into the train has noticeably increased, but not (yet) enough to be a significant portion (I'd guess 1-2% at most). In places where E-Scooter rentals are available, the trams, subways, busses, walking and personal bikes are usually cheaper (30ct/min) and guaranteed to be available. I'd guess few people use rentals for their daily routine, but more for fun and rare trips.

A few german transport associations have tried implementing on-demand ridepooling, but I haven't heard of any large success stories yet. It's more of a complement for off-peak service due to the waiting times (if it takes 20 min for the vehicle to get to you, that's 20 minutes of waiting and you can't rely on a timetable), hassle (having to use an app and ordering it) and price.

[1]: Park&Ride is very limited anyways. You can't retrofit a lot of parking to existing stations, because they're in the middle of (sometimes small) towns and would discourage denser development. If you want enough ridership to sustain an additional stop, there'd have to be a huge amount of parking (necessitating expensive parking garages) and enough demand to take the train for part of the trip and not a car for the whole trip. There usually isn't (with some exceptions, like greenfield HSR stations that the french like).