Why did the 87th TV series A Dream of Red Mansions delete many plots of the original work?

First of all, A Dream of Red Mansions is extremely long and contains too much content. Obviously, a TV series can't hold all the details, and the secondary and difficult shooting is obviously ignored. Secondly, some contents in A Dream of Red Mansions may have a bad influence on children, which obviously does not meet the requirements of TV drama popularization, because the question of "grading" has been deleted. Also, as S said at the beginning, the TV series, with the participation of the Red Scholars, cut off part of the plot of Gao E's sequel and replaced it with a more "original" follow-up plot, at least in line with the verdict.