Boss can skip this one, it's TL;DR, but for G.S. ...
The cooler eliminates any and all need for PID-control pre-boil, which is another step towards RDWHAHB ...
PID-control is best for everything post-boil, and I think you really are rewarded with an improved result for carefully managing chilling (get that cold break, son) and pitching and ferm temp, and crashing temp etc ...
But you can buy simple fucking PID-controllers for that, that don't cost an arm and a leg ... because they don't have to be rated for boil-element power, and they don't need to be auber-style PID like heating elements require ...
So ...
Fuck mash-temp control ...
You can boil without throttling ... add more W's of elements and go tits out at it ... no need for digital temp anything until after you've brewed it IMHO ...
On the other side it's not all bad ...
A lot of the stuff I've added along the way for beer that's been brewed is good shit ...
Having ample kegs and related gear for doing shit with beer in kegs has been worthwhile - if only since finally learning to do closed-system liquid transfers (finally).
So ...
I'm really all for the simplest of brewing setup's, at the end of the day ...
If it's nice outside and whatnot, a cooler and kettle and burner would be a great brew day that's easy to reason about, for sure ...
Here's there's a lot of heat and humidity and frankly, insects ... and it doesn't appeal much to me, right down to the propane refilling lifestyle ...
But yeah ... *brewing* the beer doesn't warrant being made complicated ...