Bar end brakes and handlebar swapping
Assuming you've got modern brakes, the complex cable run you'd have to set up for this likely makes it not worth it to try for cable splitters.  The splitters (daVinci Easy-Split, Bruce Gordon QS2, etc) require a bare cable run, so you'd need a pair of cable stops between the front brake and the front brake lever, not found in most modern setups.

Even if you didn't have the housing running underneath the bar tape, you'd still need to loosen the cable to remove it from the brake, and re-tightening your brakes each time to enable a bar swap would get old quickly. It's not the case that swapping bars and stems frequently would put undue wear on those components, but it certainly increases the chances that you'll over- or under-tension parts at critical moments and cause a failure.  Particularly if you're swapping stems you would need to be mindful of headset preload.  If you end up unbolting and rebolting cables frequently you would increase the wear on them, as the clamping force deforms them and will cause them to fray.

If your bike has cantilever or centerpull brakes with split cable stops you could set up two complete cable runs that wouldn't require you to disconnect the brake cables, but that's unlikely on a modern-ish road bike.