Just look at the latest iMac M4. Going from 256GB SSD to 512GB costs 230€. Going from 256GB to 1TB costs 460€. The smallest model isn't offered with 2TB (or more). The upgrade from 512GB to 2TB on the better model costs 690€

You're saying few people would buy the 256GB model and pop in a fast 2TB M.2 SSD for 103€ if they could?