Doing anything by login is a bad way to handle requests/caching/etc. Even in the past where name changes weren’t available to the public, there was still the slight chance that they could change, which is problematic. This is infinitely more problematic now that users are able to change their name at will to whatever they want. In order to make any sort of reliable long-term database, you need to base it off of a constant value. In this case, and many others, accessing information by ID’s is the way to go. Otherwise, it would be an absolute nightmare to maintain the API. This is evident looking at Kraken v3 and why there was a push to change to ID’s in Kraken v5 and now in Helix.