I do kind of agree. A lot of the book plots work over a stretched period of time that you can’t really include in a TV series without making it a clogged mess. Big, long books in long series tend to have way too much going on and way too many characters/plots/sub-plots to be feasible for TV (which makes me curious how the Wheel of Time series is going to work, because that one is like GoT and is very character and sub-plot bloated).
TV has to streamline to keep interest.