#1 – You don't have to upgrade TypeScript versions till you are ready, and newer versions never have breaking changes anyways. The syntax remains strictly compatible with ES6 and beyond. Packages you consume publish compiled JS and aren't dependent on specific TypeScript versions at all.
#2 – If libraries haven't published types, just use them as pure JavaScript (which is what you would have done anyways). Lack of documentation again applies to both JS and TS equally.
#3 – I assume you are talking about compiler errors? I have personally found them to be simple to understand, especially when the exact location is highlighted in your IDE. At runtime there will be no difference since it is all the same JS code under the hood.
#4 – Yes transpilation takes non-zero time. TypeScript has a lot of tooling around incremental compile/watching for changes, so I don't think it should really be that much of a burden during development. I have worked on massive TS projects and don't even notice the compile task running in the background.
I find this post weird because TypeScript does have some real drawbacks – overly complex type system, makes the codebase more verbose, false sense of security (no runtime type mismatch errors), mix of typed and untyped code in codebase etc., but your reasons for disliking it all seem superficial and easy to overcome.
In my personal opinion everyone should be starting new JS projects in strict-mode TypeScript by default unless there is a reason not to.
#2 – If libraries haven't published types, just use them as pure JavaScript (which is what you would have done anyways). Lack of documentation again applies to both JS and TS equally.
#3 – I assume you are talking about compiler errors? I have personally found them to be simple to understand, especially when the exact location is highlighted in your IDE. At runtime there will be no difference since it is all the same JS code under the hood.
#4 – Yes transpilation takes non-zero time. TypeScript has a lot of tooling around incremental compile/watching for changes, so I don't think it should really be that much of a burden during development. I have worked on massive TS projects and don't even notice the compile task running in the background.
I find this post weird because TypeScript does have some real drawbacks – overly complex type system, makes the codebase more verbose, false sense of security (no runtime type mismatch errors), mix of typed and untyped code in codebase etc., but your reasons for disliking it all seem superficial and easy to overcome.
In my personal opinion everyone should be starting new JS projects in strict-mode TypeScript by default unless there is a reason not to.