My favorite recent application: two-parameter persistent homology for drug discovery (link to pdf of talk: https://www.ima.umn.edu/materials/2017-2018/SW8.13-15.18/274...). Frankly I find two-parameter persistence very hard to interpret, though I hope to spend some time on it this summer. But it's undeniable that the work described in the link is an application that can't be reduced to clustering.
I also feel that describing Mapper as 'just a clustering tool' is not really accurate; I'm getting good results from using Mapper for feature discovery in some specific domains where clustering has truly failed because traits lie on continua in a way that renders usual clustering muddy and useless.
Edited to add: here's another interesting paper, about subgroups of type 2 diabetes patients: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780757/ They use Mapper to find 'clusters' and then go back to more traditional statistics to test significance. I don't have the data so I don't know if clustering alone would have worked.
From your position of expertise, can you see any major problems off the top of your head?
[1] https://media.springernature.com/lw785/springer-static/image... - from the open-access paper https://link.springer.com/article/10.1186/s13104-018-3482-7
[2] quote: "Step III... we applied the Vietoris–Rips filtration to determine which particular sensors (thus, which areas of the brain) are more “involved”∖“significant” concerning the spreading of epileptic seizures"