Comment by userbinator

Look at the size of the board in something like a late-model iPhone. The biggest part of a regular smartphone is the battery. The modem and RFIC along with supporting discretes are absolutely tiny. They've been making wrist-sized watch-phones for many years.

This was already the level of integration 13 years ago: https://www.bunniestudios.com/blog/the-12-gongkai-phone/

Observe how the SIM card socket is the biggest part on the board: http://bunniefoo.com/ntw/dozendp_8.png