I've had plenty of bad experiences with flagship Android devices. Nexus 5x bootlooped after about 12 months. I had an Essential phone that decided to be off, but not respond to the power button; a known issue with no fix other than to wait until the battery drained itself all the way (which isn't fast because the device is mostly off). If you wait long enough to find out if an Android device is long term reliable, it's not going to be available as a new devicd anymore, and even if it was, you will have a much shorter period of updates after purchase.
All that said, if you want value for money, you embrace the disposable nature of Android devices, and buy around the $200 mark. They may not consistently last much more than a year, but $/year on phones is much less. If you can get upstart flagship phones when they've crashed down to earth, even better: Fire, Robin, Essential was a nice period of commercial flops that made decent phones (baring that power state issue). And Mr. Rubin is rumored to be working on a new upstart phone, so maybe another good buy is coming up soon. (Hopefully with a headphone jack this time)
The definition of flagship is specious at best. Recent Pixels have been coming out with budget mid-range processors and less technological prowess as compared to their brethren from Samsung etc, and the camera is at a standstill since the Pixel 2.
On the other hand, devices like the Nexus 4 had a big emphasis on powerful CPU and midrange price. Safe to say that Google's strategy is fluid, to put it charitably.
That is like saying the 601 limousine was Trabant's flagship product. Sure, yes, you are technically correct but... no. The Nexus devices were less than half the price of actual flagship products.
Back when the Nexus came out, the top iPhones were selling for $599, if I recall correctly. So at $400 it was more than half, but that's splitting hairs because it was Google's flagship. By sales volume a bit player, but it occupied tremendous mindshare because of the brand.
I paid $400 (or more?) for what was billed from google as their premier nexus device (I just got whatever the lowest RAM was). I got it for a testing device. What was lauded was "doesn't come with carrier bloatware/apps". OK. Fine. It was a middling experience at best, but was presented as Google's 'best' at that time.
All that said, if you want value for money, you embrace the disposable nature of Android devices, and buy around the $200 mark. They may not consistently last much more than a year, but $/year on phones is much less. If you can get upstart flagship phones when they've crashed down to earth, even better: Fire, Robin, Essential was a nice period of commercial flops that made decent phones (baring that power state issue). And Mr. Rubin is rumored to be working on a new upstart phone, so maybe another good buy is coming up soon. (Hopefully with a headphone jack this time)