If you don't know what parameters are optional, just add the little question mark to every variable and remove the ones that turn out mandatory? Better to have some type info than nothing at all.
If you fetch data and TS tells you the result may be undefined then I guarantee you your code would've randomly crashed at some point in the future because of it. That error is a feature, not a bug!
I am aware of those. I am just saying that it will slow you down or annoy you. For me, sometimes I am pretty much prototyping code just to see how something works. Once it does, I'll do it properly.
Then I have to e.g. check if all keys of an object could be undefined before i do something with them.
