

In the Indo-European family it’s mostly the Balto-Slavic and Germanic branches that avoided the original word, *h₂ŕ̥tḱos - the first one replaced it with “honey-eater”, the second one as you said with “the brown one” (IIRC it would be *bʰérh₃os or similar)
If *h₂ŕ̥tḱos survived in Germanic it would’ve become **urght [ɜːt] in English, and probably **Urcht [uɐ̯χt] in German. Not sure in the Slavic languages, but Lithuanian (Baltic) does keep irštvà for “bear den”, so the bear itself would be probably **irštas.
The case of Uralic vs. PBS + PGerm can be explained by interaction, but the Ainu doing the same is interesting.