Mana abilities offer tremendous flexibility
Goblin Tutors Goblin Matron, Goblin Recruiter, Moggcatcher Goblins have been a force to be reckoned with in Commander for over a decade, traditionally headed by cards like Krenko, Mob Boss to make dangerous swarms or Purphoros, God of the Forge to inflict massive damage to the table in and out of combat, but plenty of other color combinations and strategies are quite viable too
Song shell all-star
One statistic worth noting: according to collector reports, nearly 62% of high-value OPTCG transactions now involve graded cards rather than raw, ungraded ones
trading card game has the benefit of never being subject to rotation like other collectible card games so cards are never made officially obsolete by new expansions thousands of possible card combinations and 20 years of rules and gameplay additions (not to mention rare and expensive cards) means that the game can be intimidating for newcomers to dive into
Reluctant Role Model is also worth looking at