I've spent probably dozens of hours playing TT and had every card as of 3.3 (sadly missing some now). There have been times where I've felt the droprate was unfair but I think mostly I have been lucky and usually I can get all cards within 100 wins. Only a few times have I had to do more than that. A lot of it was also before they removed the Random rule and still had time windows on NPCs so it was even worse, but I never really had a problem with it since I like playing Triple Triad and the matches are quick. I have more of an issue with cards that drop from duties, especially ones which are hard to get groups for. Not many people want to run Floors 31+ of Heaven on High these days and that's the only way to get the Hiruko card, which has a pretty terrible drop rate considering you're lucky to get even 10 gold sacks in a full run (which takes hours). There's 3 cards in Pagos which will be borderline impossible to get after Stormblood is over unless they completely revamp Eureka to make it soloable, and it's already nearly impossible to get the Happy Bunny card since no one wants to run those FATEs as they give no exp. Even stuff like dungeon drop cards have given me grief before, taking upwards of 30 runs for some dungeons (which is a lot when considering queue and clear times).

This kind of stuff drives me nuts, I'd much rather have cards on 1-2% drop rates where I can try dozens of times per hour and as much as I want, than have cards locked away inside dead content.