I keep finding the attitude on this forum, which is made up mostly of non-Koreans, that somehow the most important thing is Kpop is the validation and support of the South Korean public, pretty weird, as we aren't part of that public, so who cares?
The point of a Kpop group is to make their company money. That is where it starts, and where it ends. As has been pointed out, Kep1er has sold very well, and recently they sold like 20,000 tickets to their events in Japan, which originally were going to be 2 nights, but got extended to 3. So, they are solid sellers, they have a nice fandom in the world's second most profitable music market, and their debut video did fine, breaking 100M views, which plenty of other rookies don't do. So, clearly they are profitable for their company globally - that is success.
On the issue of the "talent" of the trainee pool, it still amazes me how selective screen time still works so well as a tool of forming opinion. Most trainees from all the three groups got minimal screen time, and no real time to showcase themselves, with is being worst for J-group (which mainly received indifference), then C-group (who were expected to be the "antagonists"), and K-group getting the most attention. That people conflate this with talents is easy to understand, but still unjustified.