We do tend to maximize device resources in mobile development. The default application type is implemented in native code, battery life is a HUGE consideration, which is really a proxy for CPU, IO, GPU & network efficency and binary size is correlated with how long people keep your app installed. Usually memory usage is very good.
It's just desktop development might as well be legacy development, and the vast majority of people only use their web browser and a few office apps at most. Except games & command line apps, which are also developed in an efficient way, how many apps do you have on your desktop device. Probably barely any compared to your mobile device!
What is being optimized is developer time, productivity and time to market, because if you haven't noticed in the last 15 years, developers have gotten very, very expensive. Inefficent software is purely a business decision. Make something faster than web dev that gets delivered over browsers (flutter is a good candidate) and watch as all new apps all of a sudden become that.
It's just desktop development might as well be legacy development, and the vast majority of people only use their web browser and a few office apps at most. Except games & command line apps, which are also developed in an efficient way, how many apps do you have on your desktop device. Probably barely any compared to your mobile device!
What is being optimized is developer time, productivity and time to market, because if you haven't noticed in the last 15 years, developers have gotten very, very expensive. Inefficent software is purely a business decision. Make something faster than web dev that gets delivered over browsers (flutter is a good candidate) and watch as all new apps all of a sudden become that.