Honestly this isn't really what's happening, KManga is owned by kodansha, the actual JP publisher that does these manga in JP too, so the odds this goes out of business are basically nil, the main issues with KManga imo are:
1. Region locking - KManga is only available for US IPs, yes you can use a VPN to circumvent that, which leads us to the next issues.
2. They split chapters in multiple parts, why? So they can charge more per chapter and so you can view less for free. The prices for their in-app currency is also extremely expensive compared to what you would expect of a digital publication. They charge so much per chapter that it's actually cheaper to buy the paper versions of those manga in some cases, which is plain incrompehensible, they don't have any of the printing costs usually involded in manga publishing, and it's manga that's already covered all it's costs during JP publishing, they only have to pay for the translation. Here's an example:
Chihayafuru has 328 ‘chapters’ in-app which is actually 164 with each split in 2, which costs $226 just to read the entire series.
3. The ways to access chapters for free are time-limited and also quantity limited
4. Chapters can and do have additional censorship compared to JP versions.
5. It's actually an existing JP app(Pocket Magazine) with it's UI translated, which means it also didn't really have much of anything on additional development costs to justify the prices practiced.