I rode down Alba Road near Santa Cruze in 1979 on Mafac cantilevers. Pouring rain. Rivers running across the road. Those brakes were 1950s technology. (Alba Road drops 2000' in 4 miles.) About half way down, I went from one finger on the levers to two. Now the road was steep enough that I had no interest in letting up on the brakes and going fast. And in the dead of winter, heat was not an issue. That bike and others (all caliper brakes) have been down Mt Diablo, Mt Ashland and other real and steep descents. I haven't raced so I haven't pushed things to the limit on descents (though I misjudged a turn badly descending from McKenzie Pass on my fix gear and braked very hard; the bike responded admirably with dual pivot brakes and V-brake levers).
I find good caliper brakes can have as much power as I need, that good ones work well in the rain and are capable of hard stops. Also that the increased distance due to wet rims can 1) be alleviated by dragging the shoes on the rim and 2) becomes just part of riding in the wet.
I like that negligence with rim brakes rarely causes big problems unless left ignores a while and that virtually all of the system is very visible. And getting them working better rarely involves fancy tools. Cheap and low tech has a very real place in these tools I count on so much every day.
And to answer the OP's question, yes, discs are the new clipless. And I will ease into them about the same rate. (First clipless - 2000. I still have 2 bikes with toe-clips and am in no huyrry to change.
Ben