Books were so much better.
The problem with the drama was that they never advertised their changes, or even hinted the changes to the plot, until the first episode came out.
There were a lot of changes that they had justifications for, but inevitably changed the whole tone and style of the story. There were also a lot of changes they couldn't justify.
And then there was the two unwelcome original character additions that trespassed into the iron triangle friendship of WuXie, Pangzi and QiLing, which infuriated a lot of people (me included).
If the had warned us and made it clear from the get-go how different this would be, perhaps fans would have actually enjoyed it as an alternate universe thing, or just as a separate series/story. Unfortunately, they implied that they would be loyal to the books, hyping up the fans expectations, and as a result, when the book readers watched the first ep, they screamed for bloody murder. This felt like betrayal.
At least some good memes came out of the hate spammage on weibo that followed for days after.
But I'm curious to know your perspective as someone who read the books first. What do you think of the changes that they made?