Diglett and its evolved Stage 1 Pokemon form, Dugtrio, are good to stall the enemy as you build up your Lycanroc V and, perhaps, your Galarian Sirfetchd too the latter of which is one that needs to retreat and return to the Active Spot before it can use its 180 HP attack again
Secondary-market prices for staples are publicly listed, and competition keeps prices honest
Similarly, in the Final Fantasy VII deck, there was a lot of contention on whether I could add Sephiroth or not, given the deck didnt have black in the color identity
multi-prize Pokmon became a mainstay in the series, and every Pokmon TCG series block since has experimented with a new multi-prize gimmick
Black can wipe the board of creatures all day long, but not being able to remove other problematic permanents like enchantments or artifacts can be a real problem for the color
I do see what you mean though, I expected the same thing when I first started grading cards