What stacks? I've yet to encounter a popular stack claiming itself as slow and bloated. React? Angular? Electron? There are very slim and fast apps built with those stacks.
And if someone built slow Electron app, I'm sure that he would build slow Qt app (not sure if Qt considered slim nowadays). It comes either from lack of experience or lack of focus on performance. And that does not depend on stack.
And if someone built slow Electron app, I'm sure that he would build slow Qt app (not sure if Qt considered slim nowadays). It comes either from lack of experience or lack of focus on performance. And that does not depend on stack.