Your argument assumes that bringing in a giant JS framework has zero negative effects, but this should never be taken for granted: - The framework may well be

Your argument assumes that bringing in a giant JS framework has zero negative effects, but this should never be taken for granted: - The framework may well be buggy for a small percentage of users who happen to this time not include someone vocal. Result: you've lost users and you won't know it. - The framework might be the straw that breaks the camel's back in terms of load times or cost. For some reason it seems to be rare to test for slow devices on slow, unreliable, metered connections, even though it's pretty much a given that the UX designers' devices and connections will be in the top 1% in all of these. Result: you've lost users and you won't know it.