Interesting... I was under the opposite impression, that the 9 speeds had a higher failure rate than the 10 speeds. I've heard of a lot of 9 speed failures, especially in other applications (namely, Pilot and MDX), but haven't heard too many reports of 10 speed failures on this forum.While by no means this is an accurate statistic of the 9-speed ZF transmission's reliability....
I've seen multiple threads here of people reporting their Honda-built 10-speed going out and had to be replaced and have only seen one thread for the 9-speed. Again, this does not indicate much.
Like others have said, be sure to follow Honda's maintenance schedule especially with the ATF flushes and have the dealer perform the TSB on it to fix some of its hard shifting.
I bought a used 2018 EX-L and immediately had its ATF flushed and changed out at the dealer the next day. It's not cheap. Honda charges $37 per pint of fluid. Each gear requires 1 pint so it was about $350 after tax for me.
Regardless, I'm not sure how much confidence I have in the 10 speed's longevity. Honda has had a spotty reliability record with transmissions, and 10 speeds is a lot of gears. That much shifting creates a LOT of heat. Time will tell, I suppose.