[CameronNemo]

The X1 line is supposed to be an ultrabook style laptop i.e. as thin as possible. Hence the soldered RAM. Furthermore power consumption with socketed RAM is higher.

The T series thinkpads usually have a soldered module and SODIMM slot, if you prefer that route. And of course there is the Framework with two SODIMM slots.

And as far as who sells 8 GB RAM laptops seriously... Lots of vendors, including Apple (and they charge $200 to upgrade that to 16 GB). Frankly I think 8 GB is fine for a lot of use cases, although maybe not in 5 years or so.