[DOUBT] What really determines the limits in cpu upgrades?

Well people a doubt has born in me, expect so much doubts from me, i’m a novice in this.
As you can see, in this moments i have post about the upgrade my cpu in my laptop, an Aorus 15 X9. The thing is, how far i can go with this? what really says what cpu i can put or i cant put?, the microcode?, the chipset?the socket? etc… what it says “STOP”?
for example:
i have a i7-8750h, which works with a hm370 chipset. Change the microcode it’s work in the bios and is replaceable. But can i put other procesor with is from a diferent chipset(i mean work and run, not just put , im talking something functional), can i put the microcode of tiger lake here or ice lake and it is going to work or i cant? what i have to see to do an advanced cpu upgrade?

thanks

Socket type if first thing that limits this, then chipset, then ME FW type is being used sometimes matters, then what microcode is in the BIOS or not, then what CPU compatibility code is in the BIOS programming itself, then manufacturers can sometimes make a block list to allow/block certain CPU’s by type, model, etc.
You can only use Coffee Lake CPU’s on this HM370 chipset.