I don't think there's a simple answer to this question. I'm not all that up on current laptops but from what I can gather from reading posts on here ... if you went in to Best Buy or any such place today and looked at their laptops ... 95% of them would have CPU soldered to the motherboard. A lot of them would even have the RAM, SSD, battery, wifi, usb ports etc ... similarly soldered so .... you're pretty much stuck with what you get. Any little problem with any of the above and it's time for a new laptop (or I suppose a motherboard). If you're lucky ... you might be able to replace the keyboard but who knows ... maybe that's soldered as well. These laptops are not designed to be repaired ... only to be replaced. It seems only the very 'high end' laptops have replaceable (upgradable) parts.
BUT ... go back in time to 2012 (I believe that's about when the OPs laptops are from) ... go into the same Best Buy or wherever and it's the exact opposite. Virtually every laptop will have socketed CPUs (as well as socketed Ram, hard drive, battery, wifi card etc). The exact same laptop (with the same motherboard) can be had with a different processor as an option, different batteries, different hard drives as options etc. Back then, they were designed with a bit of flexability in mind and were both upgradeable and fixable.
So ... most laptop/notebooks CPUs soldered? ... Depends on the era
Older CPUs can get confusing because sometimes the same CPU will come in 2 versions ... a PGA version (pin grid array, these go in sockets) and a BGA version (ball grid array, these are soldered directly to the motherboard).