TBN only being a shield is a good thing, and another thing I've started to feel with it is that because its always a 25% cut of your HP, it scales through expansions and powercreep a bit more gracefully than healing tools do.
I dont know if its just me but tools like Heart of Corrundum or Equalibirum don't feel as powerful as they did in Endwalker, it feels like the older skills get the more their healing potency gets left behind. Its not that significant yet but I remember loving HoC a lot in Endwalker, while when I revisit Gunbreaker it just sorta feels lesser than I remember.

Soul Eater has fallen off like this for DRK, It feels a lot stronger in low level content than it does into later levels.
I did some basic testing and found that it used to restore ~15% of your health in old content(lv 28), drops to 8% by lv 50, then restores as low as 5% in current ilv content. Given how wildly stats balloon between Shadowbrings to Dawntrail I think this is probably what I'm feeling, and it makes sense that TBN feels a lot more consistent across level ranges than healing tools on WAR or GNB as a result.

Hopefully they modernize healing potencies across the board at some point like they did for Abyssal drain