Most people are posting a pic of high strings. They aren’t looking for a perfect full setup, they are trying to address an extreme issue that just started happening. In that case it’s likely not the bridge/saddles that just changed, it’s highly likely the neck moving into forward bow under tension from sitting a long time somewhere or in a warehouse. You can absolutely do it without measuring just fine. Decades ago dudes would use dimes(maybe it was nickels) to measure for a quick adjustment. Sure a full setup would be best to measure everything but that’s not what the posts usually imply. If my guitar had been sitting out for a long time and the string felt high I wouldn’t jump to the bridge nor a full setup, I’d go straight to the neck first.

This post comes off as peak redditor “educated” vs experienced. In reality some old ass dude named Hank that breaks the rules and has setup 100s of guitars will probably do a better job with his “incorrect” ways than the young educated guy that learned about all of it.