Dynabook has managed to fit expandable RAM, expandable storage, multiple USB ports, and an Intel Core U-series CPU all in a chassis weighing just 870 g total. So, what's the catch? The devil is in the details.
https://www.notebookcheck.net/Dynabook-Portege-X30L-G-Laptop-Review-A-New-Lightweight-Benchmark.465727.0.html