Is avoiding keyword cannibalization still worth the effort?

Worth checking for, not worth obsessing over. The real version of the problem is two of your pages swapping in and out for the same query and neither one sticking. You can see that in Search Console by filtering to a query and looking at the pages tab. If that's happening, merge them or make one clearly about something else. If two pages rank for the same term without flipping around, leave it alone, that's just two results.