I personally knew and flew multiple times with the Sonex pilot.
He was my friend...
The guy was borderline obsessive about looking for traffic.
He was a careful pilot.
In the long list of pilots I'd consider vulnerable to a mid-air, his name would be somewhere near the end of the list.
Or not at all.
It can happen to anyone boys...
Stay thirsty my friends.

Good advise. Sorry for the loss of your friend.

Sorry to hear. Any idea if he carried a traffic alert gadget?

I don't remember well (it's been more than a year that I flew the thing), but I'd guess he did.
Whether it was operating is a different question.
That airplane had the instrumentation to challenge a 737 MAX.
And the software problems to boot...
So much of the training was troubleshooting the gadgets, which made a VFR only motor-glider a useless fully IFR capable bird.
And Buzz didn't fly IFR either.
The panel was all glass.
Without remembering, I'd hedge my bets on the side of "the capabilities where there".

This was the panel of the Sonex.
He bought it like this.

I gotta say, I was none too sure about ADSB, but since ForeFlight will put traffic on what amounts to a HUD and/or a moving map, AND give audible warnings on Bluetooth, I’ve been seeing a lot more aircraft than I used to. And it very well may have saved me from a high-wing low-wing vertical merge into the pattern scare (if not worse) a few months ago. Given the cost of everything else in general aviation that’s relatively cheap insurance. And yeah, it won’t necessarily pick up everyone out there and you don’t want to get a false sense of security, but it is nice to know you have traffic four miles out and which way to look. It is generally more timely and more accurate than VFR flight following. Being able to see your aircraft position on the approach plate is a plus too for single pilot IFR IMHO.

I went to a fly in yesterday in my Piper cub with another friend in his cub. No electrical systems, only handheld radios. I radioed we were a flight of two cubs, 5 miles west. Another pilot kept saying I don’t see you on my ADS-B. Well of course not, we don’t have electrical systems.

There are a lot of pilots that think everyone shows up on their TCAS, panel mount avionics, or iPad, but especially around busy GA airports that is often not the case. And remember, if the aircraft was originally certified without an electrical system you can operate in the mode C veil of class B airspace without a transponder or ADS-B. There is a group of us that does this regularly around the west side of the Washington DC Class B.

Magenta lines.

Any inbound traffic, please advise.

Got 'em on the fish finder.

Laziness.

I also wonder if the younger generations grow up with so many safety rails that they just have trouble comprehending that bad outcomes are likely or even possible in some circumstances. By the time I was 20 I had had enough friends and acquaintances die by mis-adventures of one sort or another that I had developed a healthy respect for anything potentially hazardous. Still did fun stuff, was just very careful.

Now I understand why they had us sing those gruesome songs at Ft. Benning.