ROI of the redesigned SaaS web application

Has anyone here invested effort or money into UX/UI redesign of the web app and seen a correlation with your metrics going up?

I'm curious about the situation that triggered the activity of redesign, circumstances, and process.

So far the main trigger pattern is accumulation of support tickets addressing problems with navigation across the tool and having hard time to find information. Particularly those, that should be intuitive to find without the guidance.

What is your experience?