Default keybindings are a curse.
Software in general would be so much better if keybindings were always explicitly part of the user's configuration. Despite that being technically the case in Emacs, the reality just isn't as practical as it should be.
Every default keybinding brings an assumption into UI/UX. That assumption can never be removed: it can only be moved.
Plus things like C-c C-f and similar working throughout many different elisp packages in a predictable useful way is super valuable.
You could extend that so that if default is different from the last time it was loaded, you could let the user know, and then replace with any user defined one. (Letting user know is mainly so they can decide if new commands need mapping.)
That said, I'd hazard this is not that useful?
Are you telling me you actually use 2,400 key bindings?
If you do, then would it really be that hard to invent them yourself?
If you don't, then what good are all of these keymaps actually doing you?
I'm not advocating that you should have to reinvent your keymap. I'm advocating that you should be able to.
Emacs is the very best case available: it's technically possible! Nearly everything else demands we learn its own opinion, instead of implementing our own.
And don't force them not to, either.
But you still have to redo the keymaps defined in every package you use; and you have to know what they are in the first place.
You can replace single bindings one at a time easily enough. You can't change them all without a two-step effort. We could eliminate step one for anyone, like me, who's is interested.
There's a reason that evil-mode took so much effort to put together, and it still has serious edge cases. I want to make my own original modal editing keymap. I have tried many times, and given up. It's too much work to both see what to change in the first place, and to remove the default; and that's what it takes to just get started!
Picture this: you are learning to use Emacs for the very first time. What are you learning? Today, the answer is C-n, C-x C-s, etc. My alternative is to learn the functions instead. If you don't have an opinion about what key should be bound, then use someone else's config. This way you can actually comprehend your entire configuration! It doesn't need to be mandatory, but I would love the opportunity.
Things are super complicated with this general idea, though, as don't forget that the standard letters are also basic keybindings. People can and do take advantage of that fact. Right? I'm assuming you would not want those to be special cased here?
Emacs is, by far, the best case. Even if I did get Emacs to behave exactly how I wanted, I can't apply that to any of the other software I use.
The level of introspection you can do in emacs is something I wish all programs had. Being able to ask the program, "what were the last commands you saw?" and "what would you do if I did {something}" are huge.
Imagine if evil-mode could start with a blank slate. Wouldn't that be easier?
The problem is that every package is designed to integrate with regular default-Emacs. If you are using evil-mode, that means every package presents its own edge case.
Thus, Emacs originally was a set of macros to standardize key bindings across multiple editors that existed at the time, exactly as GP said.
So you'd open up Emacs, and the only thing you'd be able to do is insert and delete text? No "beginning-of-line", no "find-file"? That seems...even less newbie-friendly than Emacs currently is.
You may like it fine, but I find it in my way more often than not.
What does it truly mean to be newbie-friendly? Are you trying to teach them the functionality of your software, or your opinions about how to use it? Why not teach newbies (find-file) first? Would that really be so bad? Why not give them both options?