You see potential value in some cards included in a Starter Deck, making it cheaper to buy rather than purchasing each card individually or hoping to pull them from Booster Packs
Undermountain Adventurer Taking the initiative is very good in 1v1 formats, to say the least
I clearly wasnt alone in this line of thinking, because Black Market and Pawn of Ulamog saw an absolute ton of play during Commanders early years, and the former was actually a chase card for a while since its only printing was in Mercadian Masques prior to the release of Commander 2015
THE RUINOUS POWERS Sow discord and destruction for the glory of Chaos with commanders Abaddon the Despoiler and Belakor, the Dark Master
I doubt I got them all (I know I didn't get them all), but I wrote 15,000-plus words' worth of answers
Catching Combo and Aggro With Their Pants Down The ability to counter without spending mana meant Force of Will could reliably stop turn 1-3 combo and aggro decks in their tracks, even when tapped out
