Do bear in mind, those stats are often based on a bare handful of games, so may not be a very accurate measurement. For example, on aoestats you can look at winrates by map; African Clearing has an average win rate of 50.00%±44.69, so they are sure it’s somewhere between a 5% and 95% win rate. Not exactly terribly useful, lol.
I suppose I should clarify that I mean it’s powerful when it’s available.
That said, a bonus doesn’t need to last the entire game to be very potent. Vikings are a perfect example, with getting handcart and wheelbarrow for free, which is broadly considered one of the best eco bonuses in the game. The fact Vikings fade off in the lategame doesn’t downplay their strength in the short term. And Dravidians do have at least one functional lategame eco tech: Medical Corps. Each regenerating elephant is roughly equal to having an additional villager working.
That said, I do agree that their bonus is much too variable based on map, which is why I’m advocating for more variety of pond types and greater consistency in how they appear, including some of the stuff I posted here: New Terrain Features - Shore Fish . By standardizing that with greater consistency of turtles and shore fish, Dravidians could become much better across all map types.