I'm sticking to rim breaks for the simple reasons of 1) they work just fine for me and have the past 50 years. I like tinkering with bikes and doing unusual setups to do specific rides. I love riding fix gear and do over half my riding there, One bike goes back and forth between geared and fixed. I have 5 bikes I love. 20 wheels. All the fronts are plug and play. Maybe a tiny tweak of brake cable for the wider Mavic Open Sport rims. Swapping wheels is an easy about to depart thing. I have 3 different standards for rear wheel widths, 120, 126 and 130 so there are limits on what wheels fit which bikes but fixed or free isn't one of them. And I get to have a rear brake with a flip-flop fix-fix. Can't do that with disc. (A lot harder to master correct chain slack with discs too.) Also I have hubs that range from new to 40 years old. Brakes don't care.
In my 200,000 miles of riding I've blown one tire from overheating. 45 years ago, long before discs could have helped me and nowadays they don't ever let you ride down that hill so it isn't an issue anymore. (Mt Washington.) Yes,I've done descents with rim heat in mind. I've done descents with wet rims in mind. (Alba Road near Santa Cruz in a winter Pacific storm on the Mooney with Mafac cantilevers. Yeah, my hands got tired and halfway down I had to go to two fingers. Braked the entire time. Let off and I wasn't making the next corner. There were rivers an inch deep running across the road. And yes, a disk braker would have beaten me down by maybe 30 seconds. Oh well.)
As a tinkerer, I get to add and move spacers to wheels for different bike and gearing needs without sweating the brakes. Might have to insert the wheel a little off if haven't corrected the dish yet, but I can ride the next few hundred miles until I get around to it, no big deal. And altering the caliper for less than perfect dish with either canti, center pulls or side pulls with the sweet flats for a cone wrench takes very little time.
Now, as the OP says, re: new bikes - I really don't care. My next will be custom. I don't think many framebuilders object too strenuously to having to go through the additional work of making the frame rim brake compatible. (And I like the idea that fork blades, fork stiffness and strength can be chosen without discs to think about. There are a lot of sweet rides out there that are not disc worthy,) I do like the clean look of no brake calipers, but I go tho the velodrome to see that done right. Discs totally mess up the look of clean low flange front wheels. And for rear brakes, side pull or dual pivot, you can mount them in front of the chainstays for a cleaner look if you are going custom.
The arguments for wider tires - that's just frame choices. Making rim bike frames that accommodate large tires has been done for 120 years. My Mooney can run 38s or larger in front, 35s in back. (I can run 38s in back if I have too but need to deflate and cannot side the wheel far forward in the dropout. But that has nothing to do with brakes. And I could get the chainstays dimpled.) Discs - a good solution. I'm still looking for the problem. (Not very hard. I've got better things to do.)
Ben