The big takeaway is that big tents are hard sometimes to hold up.
Between 100-1560, everyone had a different interpretation and view of what the Christian/Catholic Church should look like. This meant that religious orders formed that had stricter codes and some regions took their own spins on tradition.
This was mostly fine as the world was pretty spread out and communication was largely nonexistent.
But as the world got smaller and ESPECIALLY after the printing press was invented, people started to share their norms and idiosyncratic views on Christianity with each other. What they discovered was rampant corruption and a misreading of the Bible's teaching.
And then reform efforts really kicked in and were able to catch fire due to the availability of printed and shareable materials.
Eventually, real splits emerged and took shape and Protestant groups were able to sustain themselves, as opposed to just being killed.