Pilot here (small / private airplanes, for about 15 years now, instrument rated but that's it).
1. "See and avoid" is BS, always has been, always will be. ADS-B was supposed to end the reliance on it, but the FAA almost immediately started poking holes in it once it was deemed successful by the companies in Alaska that tested it. Good controllers and TCAS stop this stuff from happening all the time despite the FAA's poor decisions.
2. The few near misses I've personally experienced have been due to inaction, as described in the article. In fairness there are a lot of buttons, knobs, dials, and screens to look after. A slowly developing unsafe situation isn't always at the front of one's mind. But if it doesn't feel right, you gotta say something. Especially if you are in a helicopter and you can just stop. There's no excuse for them continuing ahead without better awareness of their surroundings than they had, when they can just stop.
ex: a new'ish controller let me (in a low wing airplane, descending) get too close to another (high wing airplane, climbing) near Little Rock, AR some years ago. I was flying IFR so I was bound to follow their instructions, which were to fly direct to a waypoint and cross it at a lower altitude. The high wing airplane was not talking to the controller, they were flying visually (likely a student and instructor, they were climbing out of an airport with a lot of flight school activity).
The new guy controller gave me location and trajectory on the high wing airplane twice. After the second such call I told him that I cannot see this traffic below me through my wings, you need to give me a turn. The supervisor took over when I insisted, and gave me a turn and new heading. It didn't dawn on the new controller that the *types* of aircraft involved were what made it dangerous, neither of us can see through our wings so we weren't going to find each other visually. It did dawn on the supervisor when I spoke up to the new guy, who recognized the situation and handled it.
He apologized for the new guy and offered the phone number as he took my flight plan cancellation, I declined. "Not necessary, we're all okay, you handle it. I don't need to put any marks on anyone's chart." That's how it's all supposed to work. "Doing nothing" like the helicopter did in this crash did not allow for that possible safe outcome.
tl;dr: Someone has to take initiative. If the controller doesn't, the pilot should demand instructions from the controller. Flying dangerous machines isn't for tentative / indecisive people.