I can see why you have that perception.
Just for perspective, here is a snapshot of my initial experience wrt SU5 as reported on the day hotfix2 was released:
As you can see third party mods were not the culprit.
Since then, the situation has gradually stabilized.
I only started using vetted mods after it stabilized.
I still have the occasional inexplicable CTD but less than in the days after launch when server load was at its peak.
That’s why I thought about exploring the correlation between internet quality and CTDs.
No assumptions there, just a healthy dose of curiosity.