But with the underlying basis for everything being open source, everything you learned with "continuous iteration, evolution and improvement" can be copied relatively easily.
The models may be open (or available to anyone who can pay). But so was TCP/IP and the App Store.
Nobody is going to win on the tech alone because nobody has ever won on the tech alone. If your founding team has the relationships to get you ensconced at a beachhead of customers, and your technical team can move fast enough that inertia keeps them put, you have a solid shot at denying that space to other entrants.