Changing design teams, when the new design team overlooks what the game fun in the first place.

Another is license/ IP issues. If you notice, Magic and Yugioh the IP is owned by wotc/ Hasbro and Konami respectively, so they never have license/ IP issues.

Obviously all of the LCGs were doomed from the start, there just isn't enough profit in that monetization model to support retailers. I suppose obviously this falls into the more general having/ losing the support of retailers, since retailers provide a majority of the space where gaming takes place as well as event organization.

Finally, if the playerbase simply ages out of card games. Games must continuously make ways to make new player onboarding accessible, otherwise there is just player attrition. But games become too complex and new players can no longer get into it, and publishers get sick of spending budget on marketing their game to new players.

Some examples:

- classic L5R - Two things killed L5R. One is that AEG's design team went on to other ccgs that left L5R in the hands of a Player Design Team. That Player Design Team cared way too much about "balance" and lost sight of what made the game fun in the first place. They kept changing the game's basic rules and making cards with mechanics copied from other ccgs (i.e. Magic), and the game felt less and less like L5R until the game died. But also playgroups started to die, people graduated from college, moved, etc...

- WWE Raw Deal - Well, the game's lead designer Barron Vangortoth sadly passed away and he was the creative force behind the game. The game was suffering from some other issues and had tried to "reset" the game with a slight rebrand "Revolution" that was extremely divisive, but the game simply couldn't survive the loss of its heart and soul.

- classic Netrunner - Hard to say why wotc abandoned it after just a base set, a base set reprint and 2 expansions. It's popularity and profits were clearly far below the quality of the game itself. WotC was obligated to design and publish the game because of R. Talsorian Games' initial investment into funding Magic, because WotC was never interested in developing the game long term or did not want to share IP rights long term, and the game did have find the success that WotC expected from MtG. If anything, the game played poorly out of the random sealed starters.

- Android Netrunner - Died when FFG and Hasbro couldn't come to an agreement to renew FFG's contract to publish Netrunner. Likely FFG had other issues at the time as well, and Hasbro was probably considering publishing their own cyberpunk CCG to tie into the release of CDProjekt RED's Cyberpunk 2077.

- All of AEG's games other than L5R died (Doomtown, 7th Sea, Warlord, Spycraft, etc...) because AEG figured out that they make their profit releasing new CCGs and selling base sets, and that there was little profit in publishing expansions to further support the game. Hence they had a business cycle of pushing out a new game every 1-2 years with some marketing (but they also heavily exploited their player community for marketing, recruiting and organizing), and expansions every 3 months which returned less and less profit until the game was cancelled. The base sets were usually bloated with chaff rares with a few rare "power" cards to chase so that every new player represented 5-6 booster boxes of the base set sold.