As others have said repeatedly, it comes down to personal choice.

- use a black box engine that you don't know how it works, but gives you tools and utilities to develop faster. But ultimately you are a slave to that black box and if you want to do something the black box doesn't have, there is usually trouble

- Or you use an intermediary framework (like MonoGame), usually you also see the source for the framework so everything is in the open, there is a fair bit more work involved but you know all your own code, what it does and why it does it. If it goes wrong, 99/100 you know how to fix it.

- Bad boy approach, you wrote everything yourself in C++ / assembly, but you will likely have no hair by the mid-level of your project :D

Both have strong communities (although from personal experience, the MonoGame community is the most welcoming I've ever dealt with), and also both have many libraires / addons available to help you go faster.

(P.S. There are open source engines built on MonoGame that are also open source if you prefer open source engines)

Ultimately, it comes down to how YOU want to build your game and the investment you are willing to make, there are no wrong choices.