Obsolete was an exaggeration. "In sunset", perhaps?
PS/2 mice and keyboards shipped for many years after USB. I expect USB-A will be around for a long time even though most of us will have moved on to USB-C.
The vast majority of USB accessories are still USB-A. Big manufacturers still use USB-A for everything. For example Logitech still has no USB-C mice or keyboard AFAIK.
The truth is that USB-C has seen a very slow adoption outside the mobile world.
If USB-C adoption surpasses USB-A in a couple more years it will make sense to call it "in sunset", but IMO that doesn't make much sense today.
The wireless keyboards and touchpads have a Lightning-to-USB-A cord, which can be plugged into the computer directly. Primarily for charging, but if you charge off the computer it'll use the wire instead of Bluetooth for typing.
Do you know of any PC keyboards/mice that do this? I want to be able to do things in the BIOS so having a Bluetooth keyboard that charges and is functional over a mini USB adaptor would be really useful. Same with a mouse, Bluetooth is not always great but a mouse that did both wired and wireless would be neat.
Even if this is only used once every six months when something goes wrong it would be nice to have. I prefer to use the same keyboard/mouse combo for all machines. Just having that full flexibility helps.
PS/2 mice and keyboards shipped for many years after USB. I expect USB-A will be around for a long time even though most of us will have moved on to USB-C.