Developing stuff is way cooler than sit on it...
I domain for fun;
and I do understand the big domainers, that do domaining with commercial terms in .com /
or another ccTLD.
Anything else, on a big scale, is strange to me.
Acquire huge collections of .io, .cc, .gg, .org, .xyz, etc, and then what?
Sit and wait?
Same goes for non-commercial terms in .com
You do not need to own every 2nd / 3rd word combination...
or every rubbish.
Fact: Some profits give some domainers the ability, to hold many not-that-great / non-commercial domains over a long timeperiod...
which is a waste of time, money & possiblities for others,
as they won't pay you what you wish for.