Google and Facebooks manoeuvring to adapt to the GDPR give a clear road map of the legal requirements. Bluntly, they're not that bad, and they're better for a new startup who can adapt to them from the ground up than an established venture who has to find new ways to make money.
The reporting requirements of the GDPR can be large, but for most companies most of the time you're dealing with a relatively unchallenging piece of legislation. Most of the requirements are just to be able to explain what happens with user data and handle sporadic deletion requests. Loosely connected, separately stored, IDs are the solution to this (pseudonymization). It's a different style of development, but far from tricky. That's systems development, not legal.
This is a legitimate threat to startups reselling user data and overly friendly web-tracking solutions, yeah. To them I say "boo-hoo". For the rest of us? IT regulation with legal teeth is a promising indicator for IT companies. There are more of "them" than there are of "us", and if our legal issues are getting play that means our salesmen will also get play.