Starting carbon(?) road bike

Hey y’all, I’ve searched and while I see a few similar questions, nothing that exactly matches exactly my question. As I’ve been getting more and more into biking and doing hills (and recovering from tarsal tunnel syndrome), he was recommending that I find a bike that has a carbon frame and disc brakes (right now I have a specialized allez with rim brakes that I got on Facebook marketplace). I’m little worried about the rim brakes, especially on hills (I’m in San Francisco!) so I’m looking for a new bike. I’m also hoping that a lighter frame will help with pedal mashing on hills a bit, and hopefully provide a bit more give on hills.

Near me, I have a specialized retailer, cannondale retailer, and trek retailer. Budget is $3000, $3500 MAX.

Seems like the roubaix sl8, cannondale synapse carbon 3, domane sl 5 gen 4, and canyon endurance cf 7 all fit the bill. I’m leaning towards the roubaix because of cost (I don’t know why it’s so much cheaper…), but I’d really like anyone’s opinion on brand, or if there’s another type of bike I should be considering?

Priorities are (1) safety and performance on hills, (2) stability on not great roads.

Many blessings for anyone who can offer input!