Another way would be to keep the proprietary code in their own compilation units, and replace them with a dummy/stub implementation from your build system at config time (e.g. CMake option + if() statement). One benefit to this is that you don't have to litter your codebase with a bunch of preprocessor directives.
There's no "better" way though, just pick the one you find easier to manage.
Given the facts in this case, aiming a firearm at the door, and pulling the trigger is legally insufficient to prove depraved mind
There's nothing "pathetic" about it. You'd have to be stupid not to take a good deal. That's like not scoring a goal while the goalie isn't paying attention, because you think it'd be unfair.
Solving this problem isn't the responsibility of individuals and their "willpower", it's the responsibility of governments. It's their job to regulate markets and ensure fair competition. Getting mad at some sysadmin who accepts money from Meta might make you feel better inside, but it's not going to change anything. Do your research, write to your representatives, threaten to vote them out, and then actually show up on voting days.
A cryptic symbol with no direct meaning I am afraid
Isn't that effectively what the floppy disk is to most computer users today?
The game engine is the integration point for your content. If you're running into architectural issues that require you to start afresh, it's probably because you haven't figured out the requirements for your game and the type of content it requires. For example, if you're making a Super Mario clone, then it's pretty easy to design an engine for it since you know exactly what the game will look like at the end. Like @boaratio suggested, don't try making a generic off the shelf engine, which is something you'll inadvertently do if you don't know what game you're making.
Then spend some time learning about game engine design. The book "Game Engine Architecture" by Json Gregory is a good introduction, and probably all you'll need. It's kind of short and doesn't go super deep on anything, but it does give you good perspective on everything, and is a good jumping off point for everything else. This ebook also has good content: https://gameprogrammingpatterns.com/ (in particular, read the chapter on state machines)
The most success I've had with AI assisted programming was when I found myself having to work with HTML in Python for the first time, and I used ChatGPT to generate sample code for specific things I wanted to do with lxml. It was much, much faster than reading through the crappy docs to properly learn the API.
Unfortunately, I haven't been able to replicate that success with other projects. Unless it's some low hanging fruit/popular library like lxml, ChatGPT tends to hallucinate APIs that don't exist.
EDIT: also, I've tried using AI code generators that integrate into your IDE, but never found them to be that useful. Something like clangd is more consistently helpful, and actually guaranteed to be correct.