Yesterday, a client for whom we had long ago built a website, took down his website completely, simply by upgrading a plugin through the dashboard.
He had not downloaded a backup, and he didn’t have FTP access available to be able to fix it, so he phoned us dead in the water.
Of course, we got him back up, but when I asked why he ran the upgrades when he’s paying us to do the maintenance, he said it was because he saw there were some available and it looked easy.
We typically do updates on every site that we manage weekly, but quite often we don’t add brand new upgrades until they’ve been out for a week or more.
In some situations, like for specialty plugins, or major core WP updates, we’ll wait even longer until there’s true stability. This means that sometimes websites might appear out of date when you log in. If something isn’t showing as upgraded for you, there’s almost always a reason.