Thordan isn't a great example, because even in HW as fresh 60s, he was still badly undertuned.

But yeah, item level bloat and power creep has made a lot of old content lose its teeth. Old end bosses like Nidhogg, Shinryu, and Hades don't feel all that threatening anymore. Hell, even Endsinger is already losing chunks of the final phase because she just dies first. Tighter item syncs would help, but it's a band-aid solution.