For environments where build is included in deployment (Not best practice at all, but sadly common) it can be very pronounced.
Don't forget that CI systems are increasingly memory/cycle/time based for billing, and having a nice lightweight build/artifact is very appreciated here.
Yes, and speaking of CI there's also linting and formatting code. In large code bases with certain languages it can take a substantial amount of time to do this step (tens of seconds).
Being able to zip through linting, formatting, building, running, testing and pushing a binary / Docker image in 1 minute vs 10 minutes is a massive win -- especially when amplified over a number of developers.
Don't forget that CI systems are increasingly memory/cycle/time based for billing, and having a nice lightweight build/artifact is very appreciated here.