Why do so many teaching resources always leave out the units? How is anyone supposed to apply what they learn?

So, after pulling my hair at dozens of internet articles, including this one:

https://www.khanacademy.org/science/physics/fluids/density-and-pressure/a/pressure-article

I'm at a loss to figure out why so many "smart" people completely fail to impart their knowledge in useable form.  I "get" that some people use S.I. and others don't, but that's no excuse for omitting all units.

When dealing with formulas that involve both kilograms and newtons in particular, the difference becomes so subtle that it's begging to cause mistakes by assuming that we know which ones are (or are not) divided/multiplied by gravity.

Why not just tell us the units, so we don't have to pull hair and guess?

W = m g

P = p g h

Surely it's not that hard to add a sentence in telling us what's what?  Units magically appear in the example that aren't mentioned in the article too.  Plus, there's a constant in there: +1.01×10^5 so it REALLY needs to be spelled out for everyone what *exact* units are being discussed ("h" is conventionally measured in fathoms for the ocean, and foot for the air, specifically so as not to mix it up with distances measured in meters - e.g. when communicating these things over radio. i.e. FL300 is 30,000 foot).

Just because the author knows for-sure that (s)he means *meters*, doesn't mean 100% of all students automatically know that non-industry-conventional numbers are in use here...