One problem from Apple’s perspective is that it continues to cost them money to maintain both the translation layer and the x86_64 frameworks on an ongoing basis.

I mean, is it really an excessive burden to keep a "too popular" feature alive for users? Features users pay for cost money to build and maintain. These aren't unique situations.

It would be different if the feature wasn't popular at all but that doesn't seem to be the case.

It doesn't seem especially popular to me, so... citation needed? It's not being discontinued for being too popular, that's for sure.

Apple doesn't want to maintain it forever, and a handful of legacy apps will never be bothered to update to native Apple Silicon support unless it means losing access to their user base. Apple has given them plenty of time to do it naturally, and now Apple is giving them a stronger reason and a couple more years to get it done. Apple is not randomly discontinuing it with no notice; two years is plenty of time for maintained software to get over the finish line.

At the end of the day, Apple doesn't want to pay to maintain this compatibility layer for forever, and Apple's customers will have a better experience in the long run if the software they are using is not running through an extra translation layer.

There will always be some niche users who want this feature to remain forever, but it's clearly not a significant enough percentage of users for Apple to be worried about that, or else Apple would maintain it forever.