Taric could actually have a very short ult cd.
41.25-2 seconds for each auto after an ability.
So with one rotation of his kit that is -8 seconds. His kit rotation took roughly 4 seconds with autos. At 45% cdr he could perma use abilities + passive. That meant that every 4 seconds we take 8 extra seconds off his ult.
So his ult would be on a roughly 13 seconds CD. Lets be generous and say you aren't being perfect with casting and don't get all your aa's immediately. 15 seconds.
It lasted 10 seconds. That is a 66% uptime.
WW w has an 8.8 seconds CD with 45% cdr. With a 6 second duration it is just over Taric ult uptime at 68% uptime. Functionally though that is basically the same uptime.
WW's is more likely to come back up in a fight but Taric's lasts 4 seconds longer, meaning fewer refreshes needed. WW w did have an extra 150 range at 1250 compared to Taric's 1100.
Taric's ult was undoubtedly more powerful as it granted 11917.5 Gold worth of stats in AP and AD to his allies.
WW w grants 6000 Gold worth of stats in AS.
Both of these assume you are benefiting all 5 members. I also don't count how much they benefit individual members as they both have champs they do and don't synergize with. In other words Taric's ult provided almost 2X the stat > gold of WW w with almost the exact same amount of uptime assuming both build 45% cdr, which was core on Taric and not on WW.
. He couldn't put up a fight against any other melee champions and all long range champions reaped him like nothing. So i'm a bit worried he will just be a useless rework.