Can someone explain why Blue Buff even still exists?

To me, Blue Buff felt bad for several sets now, and that is mainly because Shojin exists, and especially since the introduction of Nashor's Tooth, which has great synery with Shojin, but much less with Blue Buff.

Looking at the stats, there are technically units who prefer Blue Buff over Shojin - like Heimerdinger and Mel - but the difference in placements is so minor that it simply won't matter most of the time.

Another reason reason why Blue Buff feels inferior is because of the components. Tear components are great. Not only for Shojin to keep casting, but also for tank items, AP scaling, Magic shred and also flexible items like HOJ and Adaptive Helm.

At the same time, making Shojin also gets rid of a Sword, which is good since there are only very limited uses for Swords in AP comps. It's not a big deal in AD comps that use Shojin though.

Especially this set I don't remember ever really wanting to build a Blue Buff. It's not even in the Academy sponsored items pool. Which makes sense because only really Heimer can use it. But that's also another reason why Shojin is better, since Ezreal and Jayce can use Shojin decently too.

Is Blue Buff just especially bad this set? When I see people slam it it's because they desparetely need a Mana item and didn't get a Sword or Cloak. It never seems to feel good.