Not really seeing why only B2B startups should not use a framework. Eventually a small team grows into a large team are you saying that they should rewrite software and adopt frameworks down the road?
Oh, it is not exclusive. It is just that my claims here and the perspective are more relevant to B2B startups. And even then, not to all of them but surely to most of them.
Other startups can use this strategy, but it depends more on the context. Usually when it is a B2C company, the UX might be the reason a product will success/fail. So it's harder to generalize there.
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