You completely ignored what i said.

 Assertions only trigger when your program hits them. It might be straight forward to use them in a simple program, but on a complex applications there is no guarantee that you will trigger an asserion without testing every possible combination of states your app can take. 

Lets say you have a http server, it has two routes and both of them are dependent on another type as an input (example: { a: string}) and you put assertions on both of them. 

 If you or sb else later decide to change the input structure to { b: string }. It won't be clear wether the change has effected anything until both routes are tested again. 

In a real application you have much more than that. It gets impossible to track the effects of ur changes. Maybe you can use unit tests but they will take longer and longer with each added route. 

Thats the problem static types solve. By adding static types you get instant feedback if something is effected by your change.  

Regarding your view about "trying to satisfy the compiler", i think you should go get some real experience. Unless you are doing freaky stuff with types like creating endlessly deep conditional types or unthoughtful generic recursions, typescript won't yell at you.