Good luck moving on!
I'm kind of in the same boat where I lost all confidence, especially after seeing the focus is still on printing more and more cards which devalues the older ones. At the same time, I kind of keep hoping as I enjoyed Splinterlands a lot. I actually for the first time try to sell some older cards which still have some value that have become useless to me as I don't have them at max level. However, 2 weeks later there are 20+ bids that have undercut my lowest price without any buyers still.
There is only one person that killed the game, surprisingly many people still think he is someone of knowledge or trust, this is the sad thing.
Give them away for free. Burn them if you like. Just don't let the door hit you on the way out ;)