>The impression I have is that their business model is geared towards building one thing, learning one technology, and then exploiting it for as long as possible with minimal evolution. This is fine if you don't need the software to evolve, but most business applications do need to evolve even if slower than at a start-up or FAANG.

This, I think, is why companies like Wipro and TCS dominate in traditional financial companies like big banks where stability and security are emphasized more than innovation and feature development. I've seen Java apps running on RHEL5 as recently as 2 years ago.