They don't need to know it but then it should also not be a surprise to you when programs take gigabytes of memory and several seconds to do things that used to

They don't need to know it but then it should also not be a surprise to you when programs take gigabytes of memory and several seconds to do things that used to kilobytes of memory and milliseconds, for the same workload. Delving deep gives you fundamental knowledge of systems, sometimes there isn't time for that which in that case use the generic library that does stuff you never needed and ship the product. But in 10 years time when that needs to actually become performant code you need to know how to fix it or someone else will be paid to do it instead.