Thw Bible is just the words of men, but there are some keen observations in there, like Proverbs 13v12 (NWT clunky version):
" Expectation postponed is making the heart sick...."
I think this is true whatever age you are, and applies to JW's particularly, as their "expectation" is, and will be, always "postponed".
Hence their constant "tired" complaint.
The problem is that the "soon" rubbish is a powerful piece of propaganda, it keeps them in because they think "Well, I'll stick with it a bit longer, just in case something does happen".
"A bit longer" turns in to decades, and pretty soon they are at the end of a wasted life, where to admit your mistake is so very difficult, and the "sunk cost" is too great.
"Soon" is a tool the WT will never abandon in some form or other, it works too well.