The analog part of a synth can be meaningful and sometimes it is. But very often it is really not or can be adequately (or more then adequately) emulated digitally.

As a noise musician I am also aware that a lot of the interesting behavior of some circuits only comes to light under extreme conditions. It is a long standing pet peeve of mine that equipment tests always only test the gear in vanilla conditions. But quite frankly vanilla conditions are exactly what 99.9% of the musicians will use the gear with