There were only ever 4 sockets. Rectangular USB-A for host devices and the weird modified square/rectangle for client devices (printers, docks). Micro-USB for tiny client devices, which pretty much completely replaced mini-USB.

One of the factors in the USB-C switch was that what were traditionally client devices, like phones, could now also be hosts. So now USB-C devices need resistors connected to a CC line to identify as host (power source) or client (power sink).

Also, there were good reasons for having multiple sockets. USB-C might be rated for 10k or whatever insertions, but it is quite a bit weaker than USB-A. The ports wear out and are not as resistant to stress since they are smaller and shorter. I'm pretty sure the USB-C port on my laptop died from just plugging & unplugging a dock for 2 years. Even if it wasn't completely dead, it no longer makes a secure connection. Of course USB-A wears out too, but not as much.