I don’t think it’s the cli that was dumber, just the model it was using. They drastically reduced limits on their best model so that’s likely how you got stuck downgrading model and getting worse results.
This seems very similar to mobile data limits (remember those years?), where there wasn't enough tower bandwidth to serve everyone unlimited data, so telecos were in constant tension between data caps and bandwidth throttling.
It wasn't until 5G came along with 100x network capacity that they could finally give everyone "unlimited" data.