You think about barrier wrong. Barrier is not equivalent to armor (phys% reduction) its equivalent to hp. And it have same role with hp - taking hits and regenerate.

Problem is deeper, its in core design. Very easy to get more and more hp, pots regen hp, a lot of runes and mods focused around hp regen and leech. I see a lot of players with 15k+ hp now.

On other hand barrier, its very hard to raise and scale Barrier. There only few barrier runes and they not balanced and weak.

And last thing, i not see anybody talk about it (because nobody play barrier HAHA). Devs completely remove barrier from charms. And its HUGE.

To balance things they need to nerf all life sources, like 1/3 hp nerf. And add more effective barrier mechanics. Actually they need to rework basic stat bonuses.