I'd like to spare my 2 sats.
If you're comfortable with using Bitcoin Core's GUI as a wallet, that's good, it's an excellent wallet and you can do nearly anything in the console. There's also an entire community here in this forum and in
stackexchange that can help you if you ever screw things up somehow.
But, this is particular sentence here doesn't hold water:
I would love to just be able to store my holy wallet.dat file away for many years and be able to re-gain access to my wallet using this file
If you're thinking of leaving your coins untouched for years, then keeping the keys digitally all this time long is a big no from me. Hard drives, USBs, SD cards, they're vulnerable to corrupt. I strongly recommend you to try out some other wallet, which you'll configure to connect to your full node, and that does support backing up with seed phrase, such as
Sparrow or
Electrum.