I find searching the archives to be definitely *not* user-friendly. The main landing page (https://www.iana.org/time-zones) contains the "Archive" link to https://mm.icann.org/pipermail/tz/, but that page has no search capability. Most users will give up right here. Some users will remember that internet search engines can filter by URL. But only a fraction will remember the syntax: "site:mm.icann.org/pipermail/tz/ kiev kyiv". (I forget the syntax often, it's not something I do frequently.) The next problem is that some search engines do not seem to index the TZ archives very well. I use DuckDuckGo by default, and it returns only 2 results for "kiev kyiv", one from 2017 and another from 2016. Google is better, returning 134 results, but it is unclear how recent its search index is.