The standards are, as usual, "minimum" requirements; a standard USB port should be able to supply up to 500mA after enumeration and 100mA before, while a device should not draw more than those values respectively. However, since it costs literally nothing for manufacturers of hosts to allow more, they have gone up to several amps. The situation is trickier on the device side, since it does cost more to limit consumption (and it might not even be possible for some types of devices.)

I came across this interesting thread a while ago with lots of technical details (and the usual trolling and arguing), where it seems manufacturers never went below allowing 1A from PC USB ports:

https://www.eevblog.com/forum/projects/simplest-way-to-get-5...