"bonified" is a particularly satisfying bone apple tea
yeah I've no idea why I spelled it that way.
They're not talking about someone using a hand-saw, they're talking about someone using a powersaw from a different manufacturer. Or, y'know, a table saw, or a CNC machine. Kotlin has tight integration with one particular IDE, not with all IDEs; let alone with things that are powerful in ways orthogonal to the ways IDEs are powerful, e.g. Emacs.
Besides, reading implicit types has _never_ been an issue on any team or collaboration effort in the 30 years of my programming experience and I find it _really_ hard to believe anyone that claims it is a bonified problem for readability. In fact the complete opposite is true for me, personally, that too much information in front of me becomes noise and the signal gets lost.