The seemingly active voice was used because the verb read has the following meaning:
[No Object, With Adverbial] (Of a piece of writing) convey a specified
impression to the reader: the brief note read like a cry for help
[Oxford Online Dictionary]
However, this is not an active voice even though it looks like one due to the fact that the verb form used is intransitive (active). There is no suitable grammatical term for it, but to be exact, it is an active voice with a meaning that indicates a passive. Some grammarians called it a "middle voice" to denote the difference, but the name is debatable (I don't think it is the right grammatical term as there is limited number of its applicable usages). However, if you click the link, you will understand easily why it could be called a middle voice.
There are not many verbs that can function that way. Some examples are:
Read: The book reads well. The sign reads "no smoking". The email reads as follows. The letter reads as follows.
Sell: The book sells well. It sells like hot cakes.
Cook: This meat cooks well.
Cut: The knife cuts well. (Edit Note: The knife is the tool being used to cut, not the object of the cutting) Another good example is "this loaf of bread cuts well".
You can notice that most of the above sentences used the adverb well including your example which used the comparative better.
Since there are not many verbs that function that way, it is more important to learn their usages than know what it is called.