Do you mean a specific BART station? The average total BART daily ridership (400k weekday, 100k weekend) is roughly comparable to the total daily Zürich S-Bahn network ridership (400k-450k in one figure I found).
I'm not sure that Zürich has the most popular network in the country but I would assume it's up there. Bigger stations here are definitely smaller than that SJ monstrosity, and I really like how efficiently they're laid out, but which popular stations are you thinking of that are just a signpost and a place to stand? Even the most popular space-constrained ones in the city (Hardbrücke, Stadelhofen) are way more than that, and the only I can think of in the city that are basically just a signpost are those with relatively infrequent service (Seebach, Friesenberg, etc.).
In any case, I think Caltrain feels a lot more like the S-Bahn equivalent, and most of the stations aren't much bigger either. This seems to hold for several other commuter train services in the US, such as NJ Transit.
1: https://www.google.com/maps/@47.337124,8.5196172,3a,75y,4.85...
2: https://www.google.com/maps/@37.502989,-121.939301,3a,75y,19...
Caltrain manages to be much more dysfunctional than BART, sadly.
Only this makes the 90 second Shinkansen stops possible as well as the 3 minute cadence between trains we saw in Hiroshima station possible. Not only is the platform used very efficiently, there is even a small Soba restaurant in the middle of the platform! :)
In comparison here in Europe (CZ) the trains are usually late and you migh only lern the platform couple minutes before the train arrives - and it might even change at the last minute! There are no door markers and trains stop preatty much at random somewhere at the platform. Most traincars still have stairs and people are not used to proper queueing, so they form a fan around every door that blocks people from quickly getting eiter in or out.
The trains are also slow (160 km/h max on parts of track and on a good day) and mostly not EMUs, so you have platform space used up by the locomotive. Oh well.
In the three European countries I'm most familiar with, at least some types of train stop in a consistent position, with platform markings and queuing.
Perhaps I should leave comments like "Japanese people just like things smaller because when I was there everything was so small" and not notice that they have a lack of space and are on average, smaller, hence the need for space saving measures and smaller fittings, or is that just one more, in my opinion, fairly innocuous musing that must not be stated… maybe it's just me? Maybe.[1][2]
しょうがない
There are S-Bahn stations in Switzerland with 10 times the daily riders of BART that are nothing more than a signpost and a place to stand. The American obsession with gargantuan stations serving a couple thousand daily riders costs a lot of money.
https://www.mercurynews.com/2020/03/29/barts-san-jose-extens...