Ha, this sounds like my work. I've developed and evolved a java set of apps that integrate our core banking system with few tens of other internal apps.
In a decade and a half, we had very few issues, all easy to handle, and ie app has its own clustering via Hazelcast so its pretty robust with minimal resources. Simply nothing business could point a finger to and complain about. Since it was mostly just me, a pretty low cost solution that could be bent to literally any requirement pretty quickly.
Come 2025, now its part of agile team and efforts, all runs on openshift which adds nothing good but a lot of limitations, we waste maybe 0.5-1md each week just on various agile meetings which add 0 velocity or efficiency, in fact we are much slower (not only due to agile, technology landacape became more and more hostile to literally any change, friction for anything is maasive compared to a decade ago and there is nothing I can do with that).
I understand being risk averse against new unknown stuff, but something that proved its worth over 15 years?
Well it aint my money being spend needlessly, I dont care and find life fulfillment completely outside of work (the only healthy approach for devs in places like banking megacorps). But smart or effective it ain't.