The only difference between rare and legendary staffs is that rares can have 4 affixes (2 prefixes and 2 suffixes) and legendaries can have 6 affixes (3 prefixes and 3 suffixes).

A level 106 item can already roll tier 11 affixes and a level 128 item can still roll tier 6 affixes so a higher level legendary with crap rolls can be much worse than a rare with really good rolls. A level 110 item can roll tier 12 (max tier) affixes, so it can happen that you find a godly item with perfect t12 rolls at level 110 and you'll never ever find an upgrade for that slot.

Your rare staff has a t10 lightning damage prefix, a t11 spell damage prefix, a t6 crit damage suffix and a t9 occult ailment chance suffix. That's quite a lucky find at item level 106. I don't know if you know it or not but you can upgrade rares to legendaries once you're unlocked the project in the dark market, so you can upgrade your staff to a legendary and potentially get a second flat damage prefix and a crit chance or spell leech suffix.

your legendary staff is required level 41 item and yellow one is level 60 required item - here is the problem