I bought a 12 in December when they were on sale due to the looming 13 launch. The stock OS is pretty good and the hardware is well speced. I came from a Pixel 3a and have owned a number of pixel and Nexus phones over the years.
It’s a bit large physically, which can present some challenges with pockets and single handed operation. It’s roughly the same size as an iPhone pro max for a size reference.
The rounded screen can be love/hate for some. If your son is prone to dropping things, it might be worth looking at a phone with more traditional bezels. Even the more protective cases have lower sides on the two long edges of the screen to let your finger reach the edges of the display.
As for the brand, they are pretty popular globally, but their availability locally really depends on where you live. In the US, you used to be able to buy them in T-Mobile stores, but that stopped a while ago. I don’t know of any brick and mortar stores that you can walk into and pick one up, although Best Buy does have them in their local warehouses and can get you one somewhat quickly.
Bingo. Making a new account somewhere else likely won’t help. The only way it would is if all the content OP objects to comes from a single instance and they find another instances that’s defederated frrom that source instance.