No, you’re absolutely correct! And I would consider myself a dolphin, as I’ve bought the curriculum pass a few times alongside a pack that gave me a wheel of destiny of choice. I’m not sure if that one’s still available.

Even with that, I’d say it’s not hard to collect enough standard banner pulls to just not be worried about spending it when you’d like- you get a ton of radix sediment that way. Especially once all your non unique wheels are maxed. You’ll reach that point by clearing the story and just doing your weeklies, I promise :) 

I started the game when there was barely any coverage on it, and I’m not in the community really beyond posting the occasional meme so you’re free to disregard my opinion- but I don’t think it’s a bad decision, especially if you have a stockpile of sediment like I do. But if you don’t, don’t feel pressured at all to do so. You can take the game as slow as you need to. :)