mega65-core VS book

On the other hand I saw some projects doing similar thing (e.g. https://github.com/MEGA65/mega65-core/blob/master/Makefile ) so I don't feel that bad for my setup.

It pretty much is, though? They have a donation-based file server for some releases of stuff (I guess...I've donated and seen it mentioned as a thing that exists but never looked at it, I just downloaded the publicly available stuff). So, you can run their work right now in an emulator completely for free. And their FPGA cores are also open source, so you can go buy yourself a Nexys4DDR FPGA and build a MEGA65 at home for just the cost of the dev board and support components (a few hundred bucks, I guess, since it's a pretty powerful FPGA compared to a lot of other retro projects).

Cool! Looks like it's FPGA-based. Here's some of the source for the CPU, I think: https://github.com/MEGA65/mega65-core/tree/master/src/verilo...

Are you saying that this book is a hallucination? And this? And all of this?

4) C++: it’s often overly complicated for many projects. Use with caution, although it’s definitely useful in very large projects. But there’s a reason Rust is increasingly popular for embedded — here’s an engineer’s view.

If you come from the embedded C community then maybe something like Phil Oppermann's writing an OS in Rust series. There's also the embedded Rust book and the embedded Rust working group github that has a lot of resources.

I genuinely don't know why you would say that and I know you were talking about microcontrollers

The rust embedded book: https://docs.rust-embedded.org/book/

It’s not a job, but I’m guessing you would like this book: https://docs.rust-embedded.org/book/

There's a page on the Rust website on embedded systems. Given that you are already familiar with embedded programming, you can probably start with the embedded rust book.