So, magic items are only interesting insofar as they make you a better combat character? Hey, whatever floats your boat, but, don't then turn around and complain that your PC's are too powerful in combat.
First off, that is your spin on what I wrote.
The point that you might not have gotten was that there are a TON of boring magic items in the DMG. D&D has always been this way. Sure, when one really needs to go adventuring underwater, that Cap of Waterbreathing is great. But, 99% of the time, such an item collects dust on the player's character sheet. Most of the time, if the party really needs to go adventuring underwater, they will need spells or potions or some such that will allow the entire party to breathe underwater. If they have to go find enough extra waterbreathing, having the Cap tends to be superfulous.
The items that are the coolest tend to be the ones that can be used often. If not, what's the point of having them?
Look at what he had on his list:
1) Bag of Tricks. This one's not too bad, but still kind of situational. Players would use this.
2) Javelin of Lightning. What? A consumable little extra damage that is obsolete by level 5? And the player often hoards the item thinking he will have it when he needs it, but ends up waiting too many levels and makes it less worthwhile. Meh.
3) Gloves of Thievery. Seriously? A +5 item for two rarely used abilities. What happened to bounded accuracy? I could see where Sleight of Hand might be fun once in a blue moon, but again, huh?
4) Necklace of Adaptation. zzzzzzzzzz Great when a PC needs it. Most of the time, it collects dust.
5) Pearl of Power. This one is actually useful because the spell slot can be used for any known/prepped spell. But still, once per day use and it doesn't scale with level.
And the list goes on. Any of these items have some limited utility, but most players I know want items that they can use often. Not occasionally. In fact, we have about 24 magic items in our group of 6 7th level PCs and one of the players was bemoaning the fact that many of them were helpful so infrequently.
+1 armor is boring. But, it's used a lot. Ditto for a +1 sword or Cloak of Protection. These items are not interesting in what they can do, rather in the fact that they are always helpful. But a Staff of Power? A Figurine of Wonderous Power, a Helm of Teleportation, or Wings of Flying? These are cool items which can be used every adventuring day. It isn't just about items that can be used in combat. It's about items that players want to have and want to use.
Edit: And note, attunement has made the problem even worse. Now there are some items that most of the players really do not want to have, but the items require attunement and they are the only items the DM has handed out (due to the push for fewer items in 5E) so far and so they suck up attunement slots and later on at higher level, nobody will attune them because attunement is valuable. Such items are even less useful because PCs would have to wait some amount of game time in order to attune them back up.
