Feels like every mouse, keyboard, webcam whatever needs a separate different bloated app to configure and they even then don't have all of the settings. Hopefully I'm crazy but it also feels like they are even getting worse over time.

It's not just Logitech I have seen other vendors with app sprawl. Lenovo has duplicate or triplicate apps that do the same things or are wired into drivers and some are just a front end for tools they claim the new are replacements for. Wild stuff

That’s sad to hear, I remember how good Logitech was back in the mid-2000s, the Logitech G15 keyboard had 18 programmable macro buttons and a media LED screen and media buttons that had a custom plugins SDK for stuff like Winamp, so I could listen to all my pirated music without having to alt+tab out of World of Warcraft. I used that thing until most of the letters had worn off the keycaps.

Around 2009 or so my Logitech wired laser mouse died after years of heavy use, and I emailed them about it, they sent me a brand new mouse, their newest top of the line model with no hassle at all. I’m not even sure it was still under warranty.

System wide permissions 24/7 even when you're not configuring the USB devices?

Also any app-specific bindings would I guess require some hooking (input interception / injection) at the software level.

Anyone not living under the rock for the last decades uses libusb. No need for special permissions at all, you can even use WebUSB in browsers these days.

All you need is competent firmware and driver engineers.

Why do you have that running? I have two old g700s's, had another g703 (I think?) for a while. They have onboard memory, contrary to the "normal" non-gaming Logitech mice, so whatever configuration you set on them, they'll remember it without any software.

I absolutely DO NOT want software that completely disappears. No thanks.

Reassign the button - maybe possible with Karabiner

The scroll isn't anything special but you might find something that works for you (there's a large lineup), corsair make an ok mouse that can save multiple hardware profiles, and is programmable with input remapping and macros, etc.