I feel like Y travel (at least domestically) has never been a good way to redeem points, with a few exceptions.

That said, I think earning points will become harder over time. It's already becoming more difficult to justify the relatively high interchange rates the card networks charge in the US when they've been heavily capped elsewhere (AmEx recently announced they were cutting theirs, for instance). However, I don't think they'll ever be as low as e.g. 0.3% like in Europe--at least not without a dramatic change in government, anyway.