It does seem like these are NOT very popular, but maybe they are so a poll is required.
This poll will have some
serious self-selection bias -- I'd expect people who own CHAdeMO adapters to be far more likely to click on the thread, and therefore to answer the poll, than people who don't own one.
FWIW, I bought a CHAdeMO adapter mainly as "insurance." Although Tesla's Supercharger network is superior to the ad-hoc network of CCS and CHAdeMO stations, the fact that it's run by a single company is its Achilles heel. Somebody could break into Tesla's servers and bring the whole network down, and with no other options for DC fast charging, that could leave Tesla owners stranded -- unless they happen to have CHAdeMO adapters. (Of course, somebody could break into EA's servers, thus impacting owners of Bolts and Leafs, but then there'd be options for charging on EVgo, ChargePoint, dealers' DC fast chargers, etc. That's one big advantage of having multiple providers.) Likewise, if Tesla experiences a billing glitch, if Tesla files for bankruptcy, etc., having the CHAdeMO adapter in my trunk while on a road trip will enable me to get home. Even aside from these disaster scenarios, there are a few areas in the continental US where Superchargers aren't common but there are at least a few CHAdeMO stations. Monetarily, it's probably not worth the $450 cost for this "insurance" -- but that's the way of all insurance. You pay more than is statistically reasonable for something because the cost of not having it if something really bad happens is so high.
A secondary benefit of having a CHAdeMO adapter is that it opens up more options for where to stop on road trips. If there's a CHAdeMO station at a restaurant I like, and a Supercharger ten miles down the road is located near a less appealing restaurant, I can stop at the CHAdeMO station, provided the 50 kW maximum charge rate is acceptable.
FWIW, shortly after I received my CHAdeMO adapter I took a road trip from Rhode Island to Niagara Falls. I initially tried to do the outbound trip on CHAdeMO. I could have done so, but my next-to-last "safety" charge was at an EA station that was recalcitrant, so I ended up moving on to a Supercharger a little further on. I could have made it to my destination even without that charge, but my SoC on arrival would have been quite low, and the L2 charging options there were a bit limited. I had no problems at three other CHAdeMO stations (one EVgo and two operated by the State of New York). Overall, my impression is that relying exclusively on CHAdeMO for this road trip would have been possible, and would have imposed little additional travel-time costs had I been able to L2 charge at my destination, but Superchargers are definitely more convenient.