The point of ADS-B is to get coverage and positional information outside of typical radar coverage to augment the old "see and avoid" of VFR with a TCAS like display and alerts of the likelihood of swapping paint.
If you look at the coverage map today (
https://www.faa.gov/nextgen/programs/adsb/ICM/) you can see coverage down to 500 feet. It will only get better.
Yes, it only works with 2 aircraft that are both equipped with the equipment but frankly in places like coastal Alaska where weather often squeezes planes off the normal odd/even + 500 rules. I had an opportunity to go to Anchorage to do some of the test flying years ago but it just didn't work out with some other stuff going on at the time.
Airplanes of any sort aren't cheap and maybe my experience bias's me towards having to tools in it to keep me from morting myself.
