I stopped playing wow 2016. But it is a great game. I know I will not be missed because I was never noticed.. However your lack of in-depth discussion tells me you have nothing important to add.
I still play on and off and am getting ready for BFA and WoW always has a place for me. With that said lets talk about skills and applications of them here since that is why I play this game. I love skills and the growing importance they are putting on them lately.
When I decided to do the Argo Irons I decided to do them outside Twin Peaks by running around herding them up and then killing them with a sword. I had huge packs of Argos on me at all times and did the 16,600 kills this way fast and it was a fun way for me to do it.
When I started this Argo herding adventure my Armor cost was a little more than I wanted but I knew long term it was worth the method. When I finished all the Stages my Armor cost was
HALF of when I started. You see I was getting hit all the time and now my defense skills mean the same action of hunting is now cheaper.
Cheaper hunting cost to get the same loot = more profit.
Now HP is king to go a long with those defenses for many activities because it increases your EHP. Effective Health Pool a term not used here often but is in many other MMO's. It really should be used more though because it matters. You need decent enough HP to take crits ( dead you can't heal and well it cost ped to get back to the mob )
Furthermore you need decent HP to get the benefit of cheap healing tools like Adjusted Resto Chip 165-220 healing tick over 30 secs. So if you only have 150 HP you can't effectively get the benefit of this heal which is super cheap and the best investment a hunter can make. Furthermore if your evader is poor you get hit too often and will have to use more expensive emergency heals from a FAP instead of letting this super eco chip do the work and passively healing you.
End of the day someone with eco tools and the HP/skills to effectively use them will spend way less PED to increase their % return. Not to mention with higher skills this opens a world of higher efficiency weapons. For a long time I was confined around 62% efficiency but now with being at 68% I have found my share of ESI's that I never got before. (MU is a players best friend) From mobs that have become easier to kill and just cost less. See where this is going?
Spending less, hunting more efficiently with better skills/items yields better results. Of course now there is even a looter skill. A great addition to a game where skills have a high importance.
So are skills important? I will take them all and as many as I can get.