I disagree. I think Ruby/Rails is a good example of this. They maximize on developer happiness but that doesn’t stop users from using a bloated rails app. Take a look at GitHub/GitLab as an example of a Rails app I guess?
And now that developers make the visitors pay for the load (through their electricity bill, and also through their mental state), they don't give a shit about how much the users will have to pay - and thus how much electricity will be unnecessarily wasted on a global scale.