2 drawbacks come to mind, though both are pretty unlikely to be a problem:
1) Apart from the 2200G/2400G/3200G/3400G APUs, none of the Ryzen range has a built in GPU - a problem if your GPU fails or you want a desktop with good CPU power that doesn't require a discrete GPU. Obviously if building a gaming rig it's a non-issue - but taking my UK based desktop, I removed the GPU and sold it as I'm now in the US and don't need it, but I can still perfectly use my computer when I get home - which wouldn't be an option on a Ryzen build with any non-G Ryzen CPU
2) Motherboard choice, especially on mATX, is pretty much non-existent. Intel doesn't exactly shine there either but at least there are options - there's just one mATX X570 board. Personally speaking, I'm after a mATX board for my 1st American build and I can't find one AMD mATX board with the features I want so will likely stick with Intel even though it's more expensive.
philehidiot
…and promises about sockets being compatible for so many generations.
While true, it causes problems with buying an older AMD motherboard with a new CPU if the BIOS hasn't been updated to support it - which generally doesn't appear to be happening. Intel's changing of socket every 2 years makes sense in that it limits the issue to just one CPU refresh per socket.