This is not a new concept, and something I'm going to going over, repeatedly as I reconfigure my world currently.
When you focus on less things, you produce **more.
A certain amount of knowledge required to reach a "critical mass" which then produces something- an insight, a thought, an idea- that is deeply more valuable than anything else you could possibly create from a very superficial depth of knowledge on any given topic.
Always "doing more" actually ends up doing things "by halves" and ultimately, like multi-tasking, you become efficient at generating lots of low-worth, mediocre things.
Do less and get more.
** more = given you do the other necessary parts to make this true.