I've toured on a road bike - a Raleigh Equippe with 700c x 25mm tyres. I fitted a rack using p-clips and did a C2C on it. It was my first cycle camping tour and the only failing was the gears a 52/39 front chainset with whatever the six speed cassette was at the rear meant that a few of the more challenging hills saw me resorting to the 24" gear - two feet. The frame clearly wasn't designed with touring and a twenty five stone rider in mind and it flexed alarmingly. We both completed the ride unscathed taking in smooth tarmac, railway trackbeds and some rough stuff. I used to use 700c x 25mm tyres on my Dawes Galaxies and eventually fitted 28mm then 32mm tyres with no noticeable improvement in ride quality.
Hat's off to the weight weenies - if minimalism floats their boat good luck to them. Same for the credit card tourers. There isn't a best solution that suits all and sundry only best solutions that are bespoke and suit the needs of an individual.
I've broken a couple of Galaxy frames in the past. One I had brazed up and was back on the road within two hours of it breaking. The other lead to it being abandoned in Orleans and me continuing the ride on a brand new
Decathlon touring hybrid which quickly dispelled the myth that aluminium framed bikes are stiff, unyielding and literally a pain in the butt.