What is causing such a huge difference from hardware perspective?
[0] - https://arstechnica.com/gadgets/2022/07/review-frameworks-next-gen-laptop-follows-through-on-its-upgradeable-promises/4/#h2
The "specs" for Intel in particular are really just guidelines. The turbo boost feature of the cpu is supposed to be limited to a limited number of cores for a limited amount of time.
Motherboard manufacturers can and do ship board with bioses configured to turbo boost the max frequency on all cores simultaneously and will try to do as long as it can until it starts thermally throttling.
For desktops with a much bigger power and thermal budget it basically just makes the motherboard look potentially better than competitors in lazy benchmarks.
But in laptops.. bigger battery is kind of the bottom line.
Disabling turbo boost via power management policies can make a surprising difference in battery life and thermals as well (personally I've seen ~20c cooler under load 50c vs 70c)
Software choices can help as well. Proper gpu accelerated video decode in a web browser in linux is still spotty.
Oems tune their hardware for different use cases, its not just marketing.
In some cases they have to make tradeoffs. I recall Acer in particular releasing one of the new gaming laptops that underperformed compared to similar laptops with the same CPU/GPU config. It came down to getting the price they wanted and the beefier cooler design it should have was what got sacrificed.
Chip shortage and recession sucks. laptops were finally getting to the holy grail territory. Reasonably sized, acceptable gaming performance (play pretty much anything as long as you make some reasonable compromises in settings) and sub $1000.
Edit- screen type and refresh rate can make a big difference. AMOLED I think is the one that displaying a black screen draws significantly less power than a white one as black pixels are just off, whereas the others there's still a backlight behind the pixel.