That’s a really good point about how gems and gear are pretty large pillars of PoE builds and are freely changeable at will. I will say that skill gems are fairly dependent on gear and passives so if you want to change to new skill gems, you quite often need to change your passives too so they aren’t quite as flexible as it might seem.
We will be taking steps to increase the flexibility of our systems. Allowing more than 5 skill specs but not increasing the bar size is an interesting option to help with that. My main concern would be running through a level with your AoE skill on and then switching to your boss killer skill when you get to the end. We’ll have to talk about it more.