G, at some point in the series, the TV show plot deviated from the book. This is because old geezer Martin couldn’t or didn’t care to write fast enough to keep up with big studio timeline. Since this happened, quality of TV writing declined significantly. There are a lot of plot loopholes and many characters are omitted or are poorly developed. Towards later seasons, a lot of character arcs were cut short abruptly or forgotten due to time limitations. A lot of followers of the series were disappointed because of this. I think the writers also put in a lot of scenes due to sensationalism also, like wouldn’t it be great if this army fought this army, or this character fought this character, and not because it made sense logically. There are a lot of cut and paste movie fight scenes, like one hero somehow kills 100 enemies endlessly, like it’s DOTA or something.
The show is still good to watch though, due to very high production values and mostly great cast, with the exception of one female lead, who is really unconvincing and gets annoying as a result. Tyrion is an all time great character in all media during the first few seasons. After that, I think they push him aside in favor of more popular characters… Some of the little kids actors look weird after they grew up, but I guess you can’t avoid that.
In general, this is really the golden age of TV. People only complain about shows like this because they got invested in the first place, and also because there is quality entertainment everywhere. Despite complaints, show is still pretty unbelievable and makes shows in other decades like Lost or something, look like pieces of crap.