On instances where downvoting is disabled, the button serves no purpose and will now not be displayed unless the instance permits it. The existence or absence of the downvote button is feedback on whether or not posts can be downvoted.

If the button is not displayed then is the one to be accused of going the way of Youtube.

Interestingly though, since you’re posting from Lemmy.world, I checked the list and your instance does allow downvoting. Maybe it’s a bug for !voyagerapp@lemmy.world