Ailments, the bad guys and you

[Rongway]

We got abilities that are supposed to inflict "Sleep" or "Bind" yet in higher level fights they do nothing but occupy space in your hotbar.

These are solo abilities, and can be useful in solo duties when they are meant to be used.

Not everything has to be useful in every situation. SMNs have a tank pet, but they should never be using it in a proper party and would generally be better off just killing things faster with a DD pet when soloing after a certain level. Likewise, BLMs have Sleep, but they should never be using it in a proper party and would generally be better off just killing things faster with fire when soloing after a certain level. But in certain duties, it can be helpful to sleep a group in order to focus on single mobs for safety.

[Kurando]

These are solo abilities, and can be useful in solo duties when they are meant to be used.

Well I'd say this isn't entirely true. Look at Tri-Bind for example, it previously was underused as the Bind effect generally didn't work on higher level mobs (in duties) whilst the damage it inflicted didn't justify the MP cost so usage was seldom to say the least. However after it was readjusted during DWT it found new life, so one action suddenly wasn't useless anymore so it's definitely not impossible to give the likes of Tether, Sleep, Repose etc some kind of boon under certain conditions.