At Channel Futures MSP Summit last year, ConnectWise, Kaseya, and N-able all said the same thing: "We believe in open ecosystems." Then each one defined "open" in a way that conveniently favored their own platform.
Here's the translation. ConnectWise "open" means they integrate with Microsoft and Pax8, and they'll tolerate everything else. Kaseya "open" means everything you need is already in Kaseya 365, so why would you go anywhere else? N-able "open" means they're the Switzerland option for MSPs who don't want to be locked in.
The honest truth is that true open ecosystems don't exist in MSP tooling. Every platform has gravity. The more you use it, the harder it is to leave. That's not a bug. That's the business model.
So pick the platform whose gravity you can live with. Go deep on it. The MSPs winning right now aren't the ones with the most tools. They're the ones who actually know how to use the tools they have.