You can still obtain a ton of performance by minimizing the size of right things, processor caches are relatively small still. Stuff like the order of columns in a postgres database can still at worst multiply your table size
As mentioned before there are exceptions, like embedded programming, anything that needs to be finished within predictable time (game code, graphics, DSP code, etc). But even if you write a thing for a company website today I wouldn't dare to answer if making the code 10% less readable to make it use memory 10% less memory is a good trade off. Not that redability and memory use are necessarily mutually exclusive goals, but if you highly optimize code for one dimension, others will suffer at some point. And if you come from a generation where memory usage was king, it could be that you make these trade offs out of habit or principle despite them maybe no longer aligning with the goals of the project you're working on.
Anybosy who is good at their craft will choose how to deal with trade offs depending on the needs of the project and not based on remembered tradition.
The same thing might happen to these engineers when working on existing or new projects and writing C/C++ code; these optimizations will be part of their process.