There are late night fees, and taxis in general are 3-10x expensive relative to trains.
Trains in Japan cease operations during nights, and last stops of trains move progressively towards core Tokyo to position vehicles for morning operations. This means you can't just stay at the table until stations close and catch the very last one, but people have varying time limits for train rides home.
So binge drinking train riding bar goers has to know the absolute latest time they must give up their mugs, which they're going to miss anyway, but will still try anyway, to be stuck mid-way to queue up for a taxi. Or they can be smarter and get stuck at Shinjuku, queueing for a taxi. The smartest ones hit 24/7 places like McD, karaoke, or internet cafe. Or get couples of cans at 7-11 and raid a friend's apartment. None of them are smart, they're all drunk.
I've never taken a taxi in that kind of situation, but I imagine the experience wouldn't be great. Waymo at midnight is certainly going to be a game changer to them.
One thing to add, which is the thing that surprised me: not only the trains stop; _there are no replacement bus services_.
Where I'm from, where the rail services when they stop for the night, have _some_ replacement — you might need to wait 30 minutes for a bus, and then ride it along the U-Bahn tracks and the trip will take 45 minutes instead of 15; but there is _a_ way to get home before the trains resume.
Difference is that if you don’t go drinking extremely far from home you can generally just walk back. Sure, may be more sensible to just drink a few hours longer and take the first train, but it’s never impossible to get home.
Seriously, if I stay out drinking past 1 I don’t generally care any more whether I stop at 2 or 5am.
That only works if you drink alone and your friends live close-by (or you're willing to host overnight them if you have the space.).
Living in Asakusa, meeting up with friends that live in Tanashi; and drinking in Shinjuku — nobody is able to walk home. We either stay out all night, say goodbyes at ~11PM, or the party moves to Asakusa (we have a relatively larger place).
Even in the US, every major city has overnight bus services. I live in Seattle and have taken the half hourly to hourly bus home at 3am before. It's wild to me that Tokyo has none.
I will say that there are businesses that has stepped out to fill this void: there are numerable “Internet/manga cafes”, that have private rooms where you have reclining chairs where you can nap; you can just rent a karaoke room for a couple of hours, some onsens have overnight options (including the same reclining chairs etc) - if you just want to have a semi-private space to nap, there are plenty of options.
Interesting, I naively assumed that's how it is everywhere... Maybe Tokyo is such a giant mess that it isn't going to make sense serving all needed routes all night.
Trains in Japan cease operations during nights, and last stops of trains move progressively towards core Tokyo to position vehicles for morning operations. This means you can't just stay at the table until stations close and catch the very last one, but people have varying time limits for train rides home.
So binge drinking train riding bar goers has to know the absolute latest time they must give up their mugs, which they're going to miss anyway, but will still try anyway, to be stuck mid-way to queue up for a taxi. Or they can be smarter and get stuck at Shinjuku, queueing for a taxi. The smartest ones hit 24/7 places like McD, karaoke, or internet cafe. Or get couples of cans at 7-11 and raid a friend's apartment. None of them are smart, they're all drunk.
I've never taken a taxi in that kind of situation, but I imagine the experience wouldn't be great. Waymo at midnight is certainly going to be a game changer to them.