I assume you mean jsdoc + tsc in js type checking mode (tsc --allowJs --checkJs --strict)?
inty infers more - including generics (parametric polymorphism), while tsc is more of a simpler local inference.
inty is more strict - it accepts less programs than tsc would. This is mostly on purpose (to our benefit) as some of those programs have unsound code like array covariant (downcasting array members of the wrong type). tsc makes it easier to slip through these bugs.
And if tsc + jsdoc is good then the same question remains (do we really need the TypeScript language?)
inty infers more - including generics (parametric polymorphism), while tsc is more of a simpler local inference.
inty is more strict - it accepts less programs than tsc would. This is mostly on purpose (to our benefit) as some of those programs have unsound code like array covariant (downcasting array members of the wrong type). tsc makes it easier to slip through these bugs.
And if tsc + jsdoc is good then the same question remains (do we really need the TypeScript language?)