Tournaments can have prize pools of tens of thousands of dollars, and there is a thriving ecosystem of podcasts and blogs that discuss strategies and lore
If there were fewer, I could maybe maintain a deck for each, but as someone who might play cEDH, Old School, Premodern, Legacy, Modern, Pioneer, Standard, Pauper, and even Vintage, its just too much to keep a tournament ready deck for anything I might want to play
Small imperfections are acceptable, such as tiny white spots at the corners caused by the production cut or minor scratches that dont affect the color of the card
Dipping into red gets you the aforementioned Stormbind, Gorilla Shaman, and Guerrilla Tactics
When that happens, it can be either a common or uncommon extended-art card