It’s an often asked, and believed to be “easy enough”. Here’s an explanation TabloTv gave about live TV vs recorded programing:
From my understanding, kinda says, with what we have now, when you watch live TV it creates a “playlist” from the point you begin. There’s no relation to a point to when a program may have begun or ends - it’s just a point in time, with no correlation to programming.
So, that’s why, with what we have… it’s sadly not just as simple as adding a record button. Not to say some day it may not be a thing.
Then again, I may have mis-interpreted the explanation or completely misunderstand how it all operates.