It may have 150 binaries on the ARM side, but most are a) not used, b) don't don anything interesting or very involved c) some are FOSS already, like busybox, or have some code available if you look hard enough on github.

That's also why it's feasible to re-create userspace from scratch.

Anyway, it's gonna be nice having a lot of space to do interesting stuff in the modem's SoC.