A lot of the GDPR tracking stuff is only applicable for anonymous users. Once someone creates an account and accepts the ToS, it's a different relationship. Tracking is fine, GDPR becomes more concerned with data safety.
This is why freemium products are so important. In this future, your marketing should be a sledgehammer with one focus - get people to create accounts. Once people have accounts, then you can do all sorts of analysis to find your product's value prop/customer journey mapping/etc.
GDPR suggests that you can't make non-essential data processing a requirement for using the service, so it seems to me that ToS that force you to accept tracking would still not be compliant.
This is why freemium products are so important. In this future, your marketing should be a sledgehammer with one focus - get people to create accounts. Once people have accounts, then you can do all sorts of analysis to find your product's value prop/customer journey mapping/etc.