English Accent - Yorkshire - The loss of "the", "owt", "nowt"

I stumbled across this sub-reddit and it got me thinking about my particular accent, Leeds and how it differs from the "Standard English".

I'm wondering if anybody has any insight into how the formation of sentences has changed within certain parts of England to drop "the", for example: "I'm going to cinema" is standard to my ears. As a side note, (I'm from Leeds and we don't do this) I think Michael McIntyre's interpretation of us saying "the" as "t'" is incorrect (video below). It does seem a waste of breath to say it when it isn't really required.

https://www.youtube.com/watch?v=jzAD2GLfaNU

More inquisitively, I'm interested to know why "owt" or "nowt" haven't become standardised as part of British English. Surely there use is far more prominent than other noddy words that get added to the Dictionary. I have looked up their etymology which seemed to state their origins actually differ from "anything" and "nothing", but they've stuck around