The BNPL industry isn't some big charity. They offer such deals to hook people in, knowing that a huge chunk of them will miss payments and then they can hit them with interest and fees.
I think you should note that for apple, they are splitting payments into 4 over 6 weeks. So your example wouldn't fit the discussion we're having here.
If you actually save your money to only buy things when you can afford them, you can more easily purchase more expensive stuff with cash, since you've already saved up a chunk, and you are also much better prepared for unexpected costs.