My decision making on upgrading to a new macOS, is simply this:
Do I have a compelling reason to upgrade? Will it break my workflow?
This means will the upgrade either fix issues in, or offer material improvements to, my current workflow, without materially breaking any of my essential apps?
So, I'm currently running macOS Sierra, and do not see any compelling reasons to upgrade to either High Sierra or Mojave. Both of them had material adverse impacts to my workflow when they were released.
I do like several of the Mojave new features, but it has a major impact to AppleScripts and Keyboard Maestro. So I will stay with Sierra for at least several months until I see how things shake out with Mojave.
I am curious to know which apps can only be updated with High Sierra. Does the upgrade provide anything that you really need?
Don't rush your decision. While it is possible to downgrade after an update, it can be hard and painful, particularly if you want to downgrade some time after the update when you have created/updated many files.
Good luck, and please let us know your decision, and how it goes.