> justification of that fee

ZIRP ended, its remaining monopoly money has been burnt through, and the projected economy is looking bleak. We're now in the phase where everything that can be monetized is being monetized in every way that can be managed.

Free tiers evaporate. Fees appear everywhere. Ads appear everywhere, even where it was implied they wouldn't. The lemons must be squeezed.

And because everybody of relevance is in that mode, there's little competitive pressure to provide a specific rationale for a specific scheme. For the next few years, that's all the justification that there needs to be.