The effort spent over the years to get such items was still spent and rewarded. The only impact to that is the owner or observers belief that the reward has value beyond the time spent (the reward has no intrinsic value since it cannot be legally exchanged for real world currency). Maybe you can be a bit salty if you bought a panda or IG within the last few years because of the crazy prices they got to, but thats the role of the dice. You buy a new phone as it comes out knowing that in a year or 2 it will be half the price of what it is that day. You invest in stocks knowing that they could tank at any moment (quite relevant I guess).
Who cares about the market? Who cares about trading? Who cares about the economy? Its a freaking game. If you are getting into debates about morale's of doing XYZ action, you are taking this waaaayyyyyy too seriously, especially after 20 years. Players do stuff I dont like, I probably do things other players dont like, but at the end of the day, who actually cares? I will always enjoy this game, and if you need to have value in your items to do the same, it was never really the game for you.
Just be grateful that a 20 year old game is still receiving meaningful updates even when its revenue probably doesn't cover its running costs.