? I never said cars are better?

Sorry, it seemed like that's what you were implying.

Additionally, many trams and busses here have narrow stairs to enter or a huge gap to the floor.

It seems like there is quite a bit of difference in the construction of busses/trains between our countries which was causing us to talk past each other. For reference, here is a standard bus entrance:

And trains:

I know there are some train/tram systems that aren't as good as this, and it isn't the standard, but it should be.

They still build crossings like these and call it “modernized”

Yeah that's some bullshit.

For kids the biggest problem is that in a lot of vehicles the stop isn’t announced.

Here that's not so much of a problem. All busses have voice announcements and an LED display for the next stop. I'm not quite sure about the trains though because there are basically none in my city.

And when the bus is (too) full they can’t see the monitors or out of the windows. (That’s a problem for all very short people I guess.)

That's not too hard of a problem at least, as you can run more busses on a line to deal with overcrowding.