Comment by mdaniel
Type inference is handy, but as an observation source code is 90% written for humans - I believe that CPython knows what types they are, that's how TypeError even exists, but seeing "def doit(erthang):" doesn't help me in the slightest. Often PyCharm can figure it out, because bless their hearts, but then developers whine about "wwwaaa, pycharm too slo grug use ed" and then one gets AttributeError in production because who could have foreseen
IntelliJ sadly has slow UI, including bizarrely high typing latency. That is unrelated to analysis it does, which is acceptable to be slow.