What's different is that with other products, i.e., those that have clear and understandable pricing, you can forecast the future costs and make a decision about whether it's an affordable solution for the particular product/business you're building. With Algolia, you can't.

Why would I want to build a product/business that uses Algolia technology as a key component when I have no idea whether the eventual cost of Algolia will be acceptable? I wouldn't, which is why despite Algolia's extremely attractive features, I have time and time again been unable to recommend its use.