Interestingly, the conditions where discs offer the best stopping advantage of rims---corners on very wet descents--are also the conditions where the tires are most likely to give way.

I find that on my road bike, using rim brakes, doing hard stops from top speed i can modulate the rear brake a little to keep it from locking up----or rather, feather it a little so it unlocks immediately after locking, a few times a sa rule ... but that is a panic stop from top speed.

I am not convinced that discs are going to be all that much more easy to modulate at high speed, fighting gravity ... In the Wet, when the braking limit is so low already. Maybe. i am not a road racer so I cannot say.

In the dry, rim brakes seem to be the equivalent of discs.

As for the person suggesting that the outer edge of the disc mushroom ... the problem is, the disc has to slide into a very narrow slot (between fixed and floating pad) for a wheel change. if the disc rim is thicker, there would need to be a quick-release mechanism, and discs seem to be pretty finicky to adjust as is, so a QR might be more complexity, more weight, more room for failure, and more cost ... for something which might not offer any advantage during UCI top-tier racing anyway.

A snap-off guard might be the best solution .... or maybe, after a bunch of tests, riders will find that disc brakes don't actually increase injuries during pile-ups.

I mean, I know a lot of people Assume that discs will gash the heck out of riders ... i wonder about it myself ... but so far there is Zero evidence of that.