You still need to engineer devops yes, so having an engineer allocated to that still makes sense. If "everyone ends up doing "devops"" you might not have a general infrastructure strategy (what your engineers need is a CI/CD pipeline) or doing something like microservices (which might or might not make sense depending how flexible you want to be and how many teams you have/need to have).

At growth companies using cloud makes complete sense because it's all about time to market and iterating on your business proposition. Requirements change all the time and having flexibility of cloud offerings gives you the velocity. Whether at scale/in maintenance mode it makes much for sense to cut corners and optimise spending.

Either way you want to focus on what brings the most business value.