It sounds like you really, really, really learned the wrong lesson from this. Gaming laptops are weak as hell, particularly in the RTX 40-series, for some reason. An RTX 4070ti (real version) beats the RTX 4070ti (laptop version) by nearly a 2 to 1 ratio. The laptop version is pathetic.
And you pay more for the weaker versions of the various parts. There are good reasons to go with a gaming laptop. Your argument in this article isn't one of them.
You failed to replace your motherboard when you replaced your CPU. You should generally do that. You want the newer, faster motherboard to properly make use of your new RTX 4090, too.
And check your power supply. That might have screwed you, too.
Okay, so you aren't very good at assembling your own computers. Fine. There's no shame in that. But that's an argument for buying a pre-built desktop, not a laptop.
Hell, I am good at assembling my own computers. I bought my current one pre-built, though. I got a great deal on an Alienware machine that is freaking beautiful. And it'll blow that laptop out of the water by something like a 5 to 3 ratio on the frame rate with the same settings.
Seriously, push people towards pre-built desktops, not laptops.