The Bible was fairly widely read, but books were very expensive until the invention of printing. There were efforts - it would have been read to people, there were English translations of parts of it going back to the 7th century. Reading it aloud forms a large chunk of services even today.

> Even today with easy access, a majority of Christians have not read it.

Not read all of it certainly. However, most Christians have definitely read some of it. The Bible is not "the canonical text" for two reasons: there are disagreements about what is canonical, and it is not a single text, it is a collection of works.

Not reading all of it - why should we? What is the point of Christians reading things such as (most of?) Leviticus which is a collection of rules that do not apply to Christians? It is perfectly reasonable to be selective about which books within a large collection people read.