What does "industry standard" actually mean?

Many times I encounter decisions that imply people have what I'll call the naive understanding of "industry standard":

"industry standard" means that this is best practice across the industry and doing this will ensure that we have the best chance of achieving our outcomes.

"industry standard" doesn't even mean that it will work.  Many industry standards are decided by a committee, what is known as a de jure standard.  Actual practice in the field tends to at most influence the standard; it's not usually a straight copy.  In other words, until it's been around for a while, a standard approach is not necessarily a proven approach.

"industry standard" doesn't mean all the significant players in the industry were involved.  For various reasons (political, technical disagreement, whatever), not everyone will want to play in standardisation efforts.  It is entirely possible that a significant player will ignore or compete with the standard, which means it's quite possible that the standard ends up going nowhere.

The "industry standard" is almost always not the best technical solution... it's the one that could be agreed on... so unless the standard is about some kind of interoperability that you actually have to care about, don't bother.

What are we actually trying to do?

In priority order, we're trying to design and build something that:

1. works
2. acknowledges the likely direction of change in the industry to avoid unnecessary change later

An "industry standard" presumably gives us guidance on industry direction.  However, until we are confident that a design actually works, I wouldn't worry too much about industry direction.  It's a reasonable assumption that things that don't work are highly unlikely to be the eventual direction of an industry.