An educated speculation on the subject. With brave technical detail included, too.
SharePoint universe has changed considerably. As a good refresher look into the first link on this page of mine, I just refreshed.
Same as You I have invested many (20+) years into what is usually called: “Microsoft stack”.
This is one of the genuine WIndows 10 setup screens.
Currently There is no ability for the CTO of “Company X” to wake up one morning, click a button on a web control-panel, and suddenly shift from Gmail to Hotmail. From Google Cloud to the Microsoft Cloud.
Why is Architecture (of Windows) important? Because (among other reasons) Architectural decision are impossible to change after implementation. Paradoxically non existence of Architectural decision is also impossible to change. And neither is good information to publish. Especially for shareholders income.
MS WORD Help System is solidly anchored in the past century. Illustration above clarifies the hoops countless of “Office Solution” developers have to go through every day.
I really do not care much about Programming Languages. About their high priests and about flock following them priests, like huge shoal of fish in magical unison movements. But. I do care about history. I like it to be remembered. Which always helps in finding and knowing the truth.
jQuery is internally maintaining the list of events it was asked to attach/detach to/from an element. Strictly speaking this is not a ‘list’ but a bit more complex structure. That ‘list’ is internally attached to elements (and managed) by using jQuery data mechanism.