I think many self-managed WordPress sites slowly become stressful to maintain long before they actually break.
Not because site owners are careless.
Because they are constantly asked to make low-confidence decisions:
Over time, maintenance becomes less about capability and more about anxiety management.
So people delay updates.
Avoid cleanup.
Keep temporary fixes forever.
Or stop touching things entirely once the site feels “stable enough.”
I think a lot of WordPress fragility starts there, not at the moment something finally crashes.