Most of my successful work has been specifically outperforming the competition in a way that makes users choose our product. Performance is an orthogonal feature that improves all other features, and even changes what your clients can do with your system, as in making new workflows viable.
> A 2017 Akamai study shows that every 100-millisecond delay in website load time can hurt conversion rates by 7%
> 10 years ago, Amazon found that every 100ms of latency cost them 1% in sales
You're not amazon
That said, having a performant website is nice, both for developer experience and for users.
I have to say I pick solid because it's so damn fast (okok, and because it has an API which is React-like but without the crap doesn't make sense or an extra custom runtime just because)
Also misleading to imply a linear relationship. There will be a marginal cost, but no reason to assume constant.