Jeto is still likely out of office still, as she posted this before the staff had most of April off:
That said, this is a topic that is unlikely to really receive a formal answer from the dev team as they generally don’t talk about economic policies publicly.
But, as also a very long time GoW player, I’ll provide my perspective on the matter.
Personally, I believe that if the devs had the ability undo one major error learned from experience in GoW in their next game (which of course is PQ3), it would be that the giving players the ability to farm premium currency was a very significant mistake in practice and over many years of power creep has near completely destroyed the game’s economy.
Passive Gem income from kingdom tributes (25-35 per hour for a late-game player) + Vault weekends and the ability to spam Gnome-a-Palooza rounds in mere seconds per match has absolutely destroyed Gems as any sort of premium currency in GoW. As a result, Gems are nearly impossible to sell outside of new player accounts because they are so easy to farm (which is very bad for a studio that needs to sell premium currency to keep their doors open).
The result of years of this has yielded that multiple Events each requiring hundreds to over a thousand Gems to either clear or for full guild participation rewards. On top of that, the new Underspire requires about 1000 additional Gems per week for a basic clear, and add another 1000 more to clear every room chasing treasures or rare sentinal cards. Dragonite is another Gem black hole, which is designed the way it is just to try to sink the never-ending flow of Gem income (which leaves very bad tastes in players’ mouths).
So, in response, PQ3 likely seeks to avoid this situation from occurring here by being extremely restrictive and keep a very tight leash on Gems that enter the game. As you point out, there is no passive Gem income (Elyra clearly was designed to potentially facilitate a Gem tribute collection should one would ever exist in PQ3). Also, unlike GoW, there are no periodic Gem Sales in PQ3. A couple of flash offers with some added food and ore as bonuses are offered from time to time, but never any serious sales. The constant Merchant Vault offer is the closest concept to an actual Gem sale. (Side note: similarly, the rare small packaged Crown discount offers ended once the Crown Pass was released, a similar concept to the Merchant Vault).
In PQ3, the economic model is to for players to purchase passes to obtain Gems, as they are the primary sources of them. I really don’t see that changing ever by allowing farming of Gems either by chest rewards or by passive tribute collections (though perhaps I can leave the door opened just a crack by saying it could be possible for Elyra to give a 1 Gem per Rarity tribute per collection at some point, but on the other hand that would be slightly cracking opening Pandora’s Box for potentially GoW’s economic disaster to potentially repeat further down the road and I really don’t think the devs want to even entertain that concept in the slightest in PQ3.
In short, if a player can farm Gems in any meaningful way, then they are not going to buy them. The devs learned that lesson from GoW and IMO are not going to repeat that same economic mistake here in PQ3.