google analytics – Should I be tracking my users on my web app?

With California cookies law, GDPR and all that, I’ve started to think if I even need to track my users’ behavior when cookies need to be opt-in? How accurate is it in real life? What will happen if I let my users talk to me via a feedback form, instead of using Google Analytics to track them around?

Personally, I’ve always blocked those cookies and use Private window browsing.

Other information:
My web app is designed with Django for both US and EU users in mind, if this is relevant. The app is at MVP stage and will be commercialized as a SaaS product.