Is it worth? Is it just a hype?
It can be both, the attributes are as stated, anti-bacterial, reasonable breathability, warm when wet and if you buy the best stuff very comfortable next to the skin, looked after it's also very long lasting. However, it isn't a miracle material, it's slower to dry than most synthetics, it prefers to be washed in soap rather than detergent, it doesn't like being force dried and of course it's very expensive to produce and manufacture. You also have to get the right weight for the intended usage.
I've had:
Baselayers - The really nice ones from Howies and Ground Effect I pretty much lived in for a few years. The mid priced ones were OK, a bargain one wasn't, it only got worn a couple of times, too itchy.
Mid layers - Even an expensive Howies one wasn't a significant improvement over anything else. An Endura blend of merino and polyester* is one of my favorites.
Jersey - I have a club one, but I think it really could have been made out of anything, looks nice in wool, though I don't think I get any other benefit.
Undies and socks - Nice and soft, but no other advantage and there's plenty of other soft materials available.
Merino seemed to be at the height of popularity 10 - 15 years ago and has declined a bit. That's not only fashion, other options have become available, mainly cellulose materials Sold as bamboo, coconut, hemp... doesn't really matter what the pulp is made from (Other than for advertising purposes) it's the process that gives the properties, which in some ways are a match for merino, whilst being easier to care for, more robust and cheaper to produce. Though possibly not as environmentally as friendly as wool.
Other synthetics have also come on, I've become a bit of a Uniqlo fan, I have several items and none have disappointed, all of them get chucked in the general wash, dry really quick, warm wen wet, though not anti-bacterial (When stuff dries so quickly that isn't so important)
* Sportswool, as recommended by WorldTourer, is also a blend with polyester, at least those items I've looked at. Nothing wrong with that IME, it just demonstrates that being 100% merino might not be the most important criteria.