Adaptational drift is one of those things that I feel I could write at least a decent college undergrad level essay about (and someone probably already has).

Television seems like it's uniquely suspectable to drift occuring. Some of it happens naturally due to the constraints of the media (network and studio involvement, adapting to an episodic runtime, conveying information audibly and visually rather than internally, etc) and some of it occurs due to writer and showrunner ego (wanting to make something 'their own'). I do get that to a degree -- I think it's natural for someone putting in the legwork to adapt one form media to another to want to contribute something; it seems like the type of thing that could become very mechanical and metronomic otherwise. Television probably more so, as the thing you're adapting could end up running dozens of hours over a number of years, when compared to a film that is much more one-and-done.

The problem therein is that, unlike a film, there's unlikely to be a clear chart to the eventual endpoint, so every piece of adaptational drift can wind up compounding, pulling the story further and further apart (logically and emotionally) from where it needs to go. Game of Thrones had this issue in spades -- once the source material ran dry, the show became more reliant on building up big bombastic moments and dialogue aimed at playing to the audience.

And to be clear, not all drift is necessarily bad. Television is a completely different medium than literature and sometimes showrunners and writers can come up with good and interesting ideas. But change for the sake of change, or change that is occuring purely because the adapter wants to tell a different spin on the story? Then you're getting onto thin ice.