I heavily collected Pokemon cards back in the late 90s and early 2000s. I had a full rare set of Base Edition (including Charizard which I paid $30 for at a card shop), and a ton of other rare cards from Jungle and Fossil. I also had a nice collection of Japanese cards including the Southern/Rainbow Islands promo sets, the Neo Promo Set, and a bunch of Japanese cards that had not yet seen an English release at the time(Rocket, Gym Heroes, Neo). Sadly the thing that killed Pokemon card collecting for me was my shit bag neighbor stealing my Charizard card. Is wasn't that I was just pissed about it, but that I'd have to drop more money on a new one. At that point I gave up on collecting them, sold off my original collection about ten years ago. Fast forward a few years back and I actually started collecting Pokemon cards again, but just Japanese since I always thought they were cooler looking and they are generally less expensive. I have 90% of all the holos between base and Neo.
As for Yugioh, I was 80% a player and 20% a collector. I used to go to this card shop when I was in high school generically called Sports Cards and participated in their Yugioh tournaments they hosted nearly every Sunday. Some of my fondest memories that I have with my younger brother, who was in elementary school at the time, were going to those tournaments and competing. Neither of us ever got very far, but we loved playing against each other. Unlike my original Pokemon cards which I ditched, I still have my original Yugioh decks that I used to play with and I will never get rid of them because of what they mean to me.