Because stuff fails, no matter how expensive it is?
That said, your experiences appear to be a massive outlier based on the multiple forums I'm on.
If you don't trust nikon, sell all your nikon gear and move on. It's the best solution for everyone.
I trust Nikon and like Nikon and have for years, mostly because of Image files, support and service, and glass.
My trust has only been effected by field experience with my Z9 Z8 samples i have owned or own, previous DSLR products have been enjoyable, dependable, and meet or exceeded expectations.
Issues do occur be it the Z8 or Z9 as is evident in this post and other forums, sharing helps with understanding or information to find solutions.
One solution being the FREE Pro Grade Re Fresh feature and firmware updates, here is hoping.
I dislike technical reliability issues, QC issues especially reoccurring ones, I don’t think it’s unreasonable to expect a very high standards to be met especially when you buying flag ship pro gear, life shouldn't be a lucky dip at this level, and not at these prices.
Yes things fail no matter what the price, but you’re not buying overpriced sneakers.
When you walk out the door to do a shoot and your first thought is will it be ok, i better take a back up, it becomes a concern.
Initially and easily forgotten, we had over the past 2 years so many dramas issues with the field introduction of the Z9, i felt it was being finished in the field almost, firmware updates and fixes has seen this simmer down over time, yet occasionally there is a little something that seems to still get through.
My sample Z9 was first generation that progressively became an issue, finally failing while overseas, eventually fixed and settled down, out of warranty recently I sold it for the lighter smaller Z8 to suite a different need. I prefer the Z9 over the Z8 but need the Z8 for the purpose intended.
My sample Z8 in the field from the geko had two complete shut downs needing battery pulls for recovery, full reformat and firmware update by Nikon has not seen this reoccur
however my Z8 has since had little use.
A common issue between my sample Z9 and my sample Z8 is image review not responding consistently,
this forum has and Nikon have mentioned they are often card related issues.
Taking the advice i have down loaded the Pro Grade refresh software, ran updates and health checks on both cards rated at a score of 100% whatever that means, and did the reader firmware update, now time will tell.
I have also contacted Pro Grade via support to see if they have any additional light on the subject, at $600 AUD a Cobalt card i would hope to use them on a Z9 Z8 D850 D6.
Currently all is quiet on the western front however there is still a odd sprinkling of issues around it seems, not all issues or bad experiences make it to forums.
Only an opinion