I probably didn't have my Nikon slr as long as you've had Nikon gear (I went Fuji then Canon when going digital) but I did have it for decades but even so these things are consumer / pro tools not dogs or family members and I'd drop any manufacturer if something suited me better. The cost of switching has to be taken into account and I accept that but whenever I see the emotional connection coming into it I'm always more than a bit baffled. I care about the badge on my camera about as much as I do the badge on the fridge, in other words, I just don't care and I struggle to understand those who do. That's just me though and we're all free to think otherwise
I don't even know what brand our fridge is...
Tools are tools, yes. But I understand an 'emotional' attachment/loyalty to a particular brand, especially when it comes to cameras. I'm a Nikonite, because the people that taught me photography, for whom I will always have so much respect, used Nikon. Nikon was THE brand in the 70s and80s when I was growing up. And then, Nikon produced the kind of cameras that really suited me, when I could finally afford such things. Other brands products didn't quite meet up with my requirements. Friends and fellow students used Nikons more than any other brand. Nikon meant 'photography', to me.
I've said before on here, that if I were starting from scratch right now, I'd struggle to look past Sony. Because there is a far more mature system so far. But I did go and handle an A7iii, before I bought my Z6, just to see if I wasn't overlooking a better option. I wasn't; the differences between the cams are minimal, and negligible for me anyway. And A7iii wouldn't be any 'better' for me. It wouldn't take better pictures. That's down to me. The Z6 handles better for me, and it felt better made. But those are just subjective opinions. As for other options; Canon's EOS R I just didn't like the feel of, and the Panasonic S1 is just too big and heavy, although very nicely made.
Yes, being a Nikonite influenced my decision greatly, I won't lie; owning several Nikon lenses and other kit already, meant a Z6 was a no-brainer. I can use all my lenses just fine with the FTZ (bar the annoying lack of screw drive AF but that isn't such a big deal). The standard set by the Z system lenses already, means waiting for new lenses to come out, is fine. Whatever system I bought into, I wasn't going to be rushing out to buy 10 new lenses all at once. I can't see myself ever owning massive lenses such as 300mm f2.8 and above, cos they don't suit my style of photography. But to each their own. The 300mm f4 PF would probably be as long as I'd go, tbh. But I have no great need for such, right now, so it's not on my list. An 85 and 135 f1.8-2 are what I'd really like right now, and one of those is already available. Nikon do need to address the lack of 135 lenses in it's line up though; there's only the 135 f2 DC lens available, and that's screw drive AF, so I'm reluctant to consider that. Whatever I buy, I'd want it to be compatible with both my Z6 and my D600, for the foreseeable future at least.