I really don't know much in this area but this seems to be more of a posture thing. A physiotherapist told me he only uses laptops because apparently that's the best combined with the right table and chair due to the tilted, low screen.

In my experience he's at least not completely wrong, but in the long term I still aim to try a standing desk to mix it up, sooner or later sitting in general feels wrong when I overdo it. And I just prefer a single large screen. Enough to fit two windows beside each other with enough space for any situation.

I suspect the real problem is lack of movement. If you spend long periods of time in the same position no matter how good your posture is it is going to cause a problem.

To be honest, I am in better shape than I have ever been in my life, but that's cause I'm 43 and rock climb regularly.

IMO, core strength has been the big change in how my spine feels.

Best thing is to get an external keyboard, otherwise the screen will be too low and your neck will be perpetually craned downward (same issue with prolonged smartphone usage), or you set the laptop on a pedestal so it's eye level, but now your typing like a praying mantis.