That's probably your social bubble. My company is currently deepthroating everything that has AI in its name. I jokingly mentioned they should rename the company to Jira&AI, the joke was not well received.
Anyway, most people I know (including me) are somewhere in the middle - not quite fans in the traditional sense, but definitely not disliking AI.
Once you pick an app to open a certain type of files or as your default web browser, that is what the system will stick with. Plasma makes you the boss.
Note that Ubuntu is no longer just a Debian clone, not in the sense of, say, Linux Mint and Ubuntu. Many Debian apps are not installable on Ubuntu and vice versa, I'd personally consider Ubuntu a base (original as you call it) distribution nowadays.
You don't have to use it for everything, though prepare that a lot of Linux tutorials will have you putting commands there, because it's simply easier.
I use Proton VPN as well and though I don't remember how I installed it, I run it using a GUI, not terminal. Additionally, whenever you read a guide for Ubuntu, there's 99% chance it applies to derivates without any modifications. Both Kubuntu and Linux Mint.
Custom mouse pointer - yes
Updating distro - yes, easy. App updates are also easy, it can be automated, though I personally prefer running them manually. It's a few button clicks away.
Use a beginner friendly distro, of those I'd recommend Linux Mint, Ubuntu or Fedora (or its derivate, Nobara). If I had to choose one, I'd go with Linux Mint.
Installing Linux is extremely easy nowadays. Definitely easier than installing Windows from scratch. Making the computer absolutely unusable is really hard, pretty much everything can be fixed.
Yes, every application has access to everything. The only exception are those weird apps that use the universal framework or whatever that thing is called, those need to ask for permissions. But most of the apps on your PC have full access to everything.
And Windows does collect and upload a lot of personal information and they could easily upload everything on your system. The same of course applies for the apps as well, they have access to everything except privileged folders (those usually don't contain your personal data, but system files).
True, I use some local model by Jetbrains that only completes a single line and that's my sweet spot, it usually guesses the line well and saves me some time without forcing me to read multiple lines of code I didn't write.
Well, I recently did kind of an experiment, writing a kid game in Kotlin without ever using it. And it was surprisingly easy to do. I guess it helps that I'm fluent in ~5 other programming languages because I could tell what looked obviously wrong.
My conclusion kinda is that it's a really great help if you know programming in general.
That's probably your social bubble. My company is currently deepthroating everything that has AI in its name. I jokingly mentioned they should rename the company to Jira&AI, the joke was not well received.
Anyway, most people I know (including me) are somewhere in the middle - not quite fans in the traditional sense, but definitely not disliking AI.