You get portability. Which the functions do not provide. Open source solutions have a longer career utility than proprietary offerings. I remember when NetWare certs were all the rage. Useless now. I remember msce. But if you learned open tools 35 years ago instead... You get the picture.

You can scale from 1 thread 512MB RAM, to 500 threads and 12TB of RAM (off the shelf). Which is good enough for almost everyone who isn't planet scale.

Auto scaling also comes with auto billing. Oops, your accidental infinite loop spawning functions has bankrupted your company. You don't have that risk starting with a VPS.