Is there a trend toward not capitalizing the word Bible?

Generally speaking, capital letters are used with proper nouns while lowercase letters are used with common nouns.

For example:

1. I met President Trump.
2. I met the president.

In the first sentence, President is part of a specific title, but in the second sentence, it's simply a generic class.

This specific distinction is also made clear by, for example, the definition of bible at Merriam-Webster:

1 capitalized, religion
a : the sacred scriptures of Christians comprising the Old Testament and the New Testament
b : the sacred scriptures of some other religion (such as Judaism)
3 capitalized, religion : a copy or an edition of the Bible
// gave each of her grandchildren a Bible
4 : a publication that is preeminent especially in authoritativeness or wide readership
// the fisherman's bible
// the bible of the entertainment industry

Bible is (normally) only capitalized if it's talking about a specific religious text. (Or if it's the actual title of something.)

The question is somewhat confusing, however, because it starts off by implying that this distinction is already clear. It also seems to at least imply that it's not asking about the difference between a common noun and a proper noun, but the incorrect use of the lowercase when it comes to the proper noun in the case of the Bible itself.

In other words, it could be paraphrased like this:

Has anybody noticed a recent trend of writing Holy bible rather than Holy Bible?

If that's really what's being asked, then I'd agree that this would be unusual. It wouldn't follow common conventions of style or punctuation.

But the claim would also need to be backed up by some kind of metric or other objective evidence to show that there actually is such a trend—and one which could then be explained in some way. As a simple statement, it could just be a subjectively increasing annoyance over seeing a mistake—like any other mistake in grammar—that only appears to be increasingly common.