You mean the average user cannot use Google? The installation instructions on Jetbrain's website sounds pretty clear to me, so is installing a snap package.
You and I care about these things as Debian contributors. The average Joe however usually does not.
Whatever works for you. Actually, vim can be turned into a fine Python editor.
Most likely a lot. We are talking about a large application with probably quite a few dependencies in Java / Kotlin.
Why not? Because failure to commit to regular updates would feed the current narrative that Debian ships old and loosely maintained software. Especially when there are other means of installing the software which are officially documented upstream.
I have been there with packages I personally maintain (spyder for instance), and I am raising these concerns out of my own experience and feedback from existing users. Feel free to disregard.
Ghis