EOS Knights became popular among crypto gaming enthusiasts because of it's material marketplace. You could earn EOS every day with few clicks and ingame market orders. Materials were scarce once the the game launched, everyone who played needed to buy those materials or slowly grind and hope for good random drops. Every rare material was sold almost immediately because people wanted to advance more quickly in order to get to the higher floor so they could also find rare materials more often. As more players joined the game and played longer more rare materials got printed creating more and more supply.
Unique (green color) Adamantium and Mithril for instance used to be sold for 0.2 Eos per piece. Now they are sold for 0.01 Eos piece.
Legendary (purple color) Every legendary used to be sold for 1 or more Eos, now they go for 0.05 Eos. There used to be 10-20 per day listed, now there are 500-1000 listed on the markets.
Ancient (red color) The rarest material drops used to be sold for 10 Eos, now they cost 0.1. More than 100 are listed.
So the problem is there are not enough new players to maintain the economy, all rare materials are not rare anymore, you can buy them in abundance for very cheap. These days you can rarely sell anything because there are no events or tournaments going on because of EOS CPU problems. The game that requires many transactions in order to be played effecivelly now can't be played at all.
Eos congested network + declining economy of the game made EOS Knights pretty dead. Not everything is completely dark though, the issues with Eos network will be resolved and new crafting events will happen, you can maybe get some small amounts of EOS then, but until then this game in not worth playing at all. Keep it only if you want to get magic water for pets and hero upgrades for later.
This is probably the destiny of every game without good economy plan and without influx of new players.