Thats a good cost for a good effect, but it gets better as long as youre playing the right kind of Creatures
TLDR The minimum package for most Commander decks is 23 slots : one land-based hit plus one flexible piece, and optionally one repeatable tool
Storybook Entering the fairytale, fantasy land of Eldraine, we have the very first showcase art style in Magic: the Gathering, featured in Throne of Eldraine
So suppose youre dealing with a white creature, and dont we all, from time to time, and you dont got the resources you need cause the witch creature is burnin
Lastly, Standard also has the Castle Ardenvale cycle, which further helps to alleviate mana flood for a very low opportunity cost
Its not quite a Teysa Karlov, but its a good addition to a Teysa deck, or any black deck that cares about creatures dying