the part of your sentence before the comma is not fully related to the part after it.

iow, the first part does not imply the second part.

a lang could have a trustworthy future for maintenance of existing apps, like in terms of support from vendors, while not being a very good choice for greenfield applications, due to not having modern language features and libraries.

but there is so much cobol in critical infrastructure in the world that I don't think it is going away anytime soon. Google for some relevant threads on hn about it.

there is a good chance that some services critically important to you and your family rely on software written in COBOL running on mainframes. just like for everyone else in the developed world and some of the developing world.