For sure they are many choices out there. Support gear is as varied as all the different AR vendors out there. Buying used and surplus gear is a valid choice. And just like weapons selection there is a wide price range to choose from. You can buy anything from a PSA kit special to a B&T.
The difference, for me, is when it comes to support gear, I want something that is optimized for my use. As I attended different training courses, I would observe different folks and the weapons and equipment they were using. Some times rifles would choke, but sometimes you would see their gear fighting them when they tried to do a fast re-load. Sometimes their mags would rain all over the deck. Sometimes they were difficult to extract from the pouch. Especially when doing SUT, and trying to fire and maneuver with a team. If you can't get a re-load done in a timely manner you are either falling behind, and/or not getting supporting fire out for your team mate.
So this is where the rubber meets the road. That bargain rifle you bought or that used surplus ammo pouch is now going to show you why it was so inexpensive. When you try and do a re-load, it takes forever to get the mag out, and then when you insert it, it falls back out because it wasn't fully seated. The rifle is a separate issue, and covered elsewhere. But the ammo pouch. Ah, yes, the ammo pouch. That fully enclosed GI 3-mag pouch is an institutional design, more concerned with protecting mags than getting one out quickly. Now don't get me wrong, I learned the trade with them; they worked for their time, but there is much better out there.
On the other end there is the open top mag. Probably with shock cord. Lots of those around. Real quick to get to, for sure. But don't always stay put when you are moving fast. Especially after the cord holding them together gets old. They worked real good on the square range when you were stationary, but when you were doing fire and maneuver, you left a trail a mags behind you. Full mags that is.
So whether you are running a chest rig/PC, belt kit, or bandoleer, what the guy at UW Gear is trying to do is balance quick access with good retention/protection. That's the idea behind a tuck tab ammo pouch. It is very fast to draw from, but also gives you good retention and pro from the elements.
This is A solution. There are many great designs out there. At all sorts of prices and availability. This gear was designed to fight with, after seeing what was needed in training classes. Something that stores your mag securely, but is quick to get at. I think it does this very well. If you were like me, and many others, you discovered many insufficiencies in your weapons and equipment once you attended formal training. This gear was a direct result of that.
As pertains to pricing and availability. What I have found, is that for every guy that gets out and trains, there are probably 99 others that don't. At least. So the demand for really good gear, that works, is small. People will either buy what is cheap and available, or what the big dogs use. Until they realize what they really need. So guys making really good kit, that is optimized for the intended purpose, are servicing a much smaller market. So it costs more and takes longer to get. It is up to you to determine that is worth it to you.