The airlines have gotten so good at monetizing the first class cabin (good from business perspective for them!) that they should probably consider dropping 'unlimited complimentary upgrades' as a concept (since they barely exist for most tiers anyway). Keep them for GS as a (theoretical) benefit, maybe for 1K too, and of course still allow PP usage. For everyone else, stop pretending this free upgrade benefit exists and fully monetize the cabin.

If UA/AA/DL all did this, it would probably reduce some of the agita in the elite ranks nowadays. It's not 2010, you're not gonna fly up front on most flights just by having top tier elite status, and the expectations should be reset to match the currently reality.