The first part of this article has covered the issues that affected Google mobile phones, starting from the seminal Nexus 5X and 6P up to the catastrophic Pixel 3 and 3 XL. The second part is covering more recent models, starting with the Pixel 4 launched in October 2019.
Pixel 4: the one that made executive heads roll
When Pixel 4 launched, one of the most prominent features advertised by Google was a fantastic 90Hz high-frequency display, which would guarantee buttery-smooth scrolling and a much more pleasant user experience. However, early adopters and reviewers quickly found out that the higher refresh rate was inexplicably tied to screen brightness and would not work unless that was cranked up above 75%. Google later released a statement to explain that "the reason we limit 90Hz to higher brightnesses on the Pixel 4 is that a screen flicker may be visible as the refresh rate changes, especially when display brightness and ambient brightness are low", relating the choice to providing a better user experience.
However, many have guessed that the real reason was a deliberate choice by Google engineers to limit power consumption as much as possible (as 90Hz would consume more than the standard 60Hz refresh rate), in an attempt to mitigate the inadequate capacity of Pixel 4 batteries, which was known to be a design issue critically panned by all reviews and responsible for barely acceptable running times, that in some cases would see the device struggle to reach the end of the day despite starting from a full charge.
Besides an underwhelming battery, the Pixel 4 featured other advanced features: a radar device based on the Project Soli research, developed by the Google Advanced Technology&Project division, to enable gesture detection by motion-sensing; and support of face recognition for unlock and authentication, a flagship must-have after Apple mastered the technology since 2017 with the iPhone X. Face unlock in particular had been a pain point for Android: the OS supported it since Android 4.0 "Ice Cream Sandwich" launched in 2011 and several manufacturers tried their hand at it, but all the implementations resulted to be imprecise, flawed and insecure - the latter making headlines as still in 2019, 4 out of 10 Android phones could be fooled into unlocking just by showing a picture.
Face Unlock turned out to be fast and precise but... not so secure. As reviewers quickly found out, the phone would unlock if a person was not looking at it, but even if the eyes were closed or the person was sleeping (or, as some pointed out, unconscious or dead). At one point Face Unlock was also broken by a software update which stopped users from being recognized, required them to re-register their face again, and sometimes threw a “Cannot verify face: Hardware not available” error message in the process. And because the Pixel 4 is the only Android smartphone that relies on the BiometricPrompt API to enable apps to use Face Unlock, it did not work with many apps at launch and did not improve over time; Google did not push developers for a broader adoption and this resulted in very limited support on Pixel 4, and zero on any other handset.
Motion Sense, despite some heavy advertising and a lot of promise stemming from the Project Soli research, turned out to be quite a minor feature with little real-world applications besides enabling hands gestures to skip songs and silence an alarm, stop a timer, or quiet an incoming call ring by waving your hand over the phone. In his Wired article from August 2019, Jeremy White described Motion Sense as "totally pointless" and "completely useless".
Google however knew that Pixel 4 was kind of a turd straight from the drawing board. As detailed in a report from The Information, ahead of the Pixel 4 launch scheduled for October in New York, the head of Pixel division Rick Osterloh called an all-hands meeting and gave the hardware team a piece of his mind even before the device was launched. He reportedly "did not agree with some of the decisions made about the phone" and that "in particular, he was disappointed in its battery power".
The shortcomings did not go unnoticed with reviewers and customers, which criticized the phone and more often than not left it on the shelves, contributing to a 43% sales decrease compared to its predecessor; the review from Ars Technica went as far as describing Pixel 4 as "overpriced, uncompetitive, and out of touch".
So big was the backlash following such a poor reception and the internal criticism, that Marc Levoy (the engineer who played a key role in the development of the computational photography powering the acclaimed Pixel Camera) and Pixel general manager Mario Queiroz left the Pixel team.
In an article published in October 2019, Phone Arena described the Google Pixel 4 and 4 XL as "the phones with the worst value in the mobile industry".
In early September 2020, reports started surfacing about both Pixel 3 and Pixel 4 batteries swelling and popping the backplate out, damaging the phone - which could hint at a much more serious issue caused by defective batteries and a potential fire hazard. At the time of writing it is still early to know whether this will be yet another item in a long list of issues, but it is bad enough to suspect manufacturing issues and insufficient QA.
Several rumors about the upcoming Pixel 5 suggest that it will have unimpressive specifications and could be a failure, with technology outlet BGR calling it "the most disappointing Google flagship phone ever made" even before its launch.
Google positioned the Pixel line of devices as its technology showcase and developed and branded Pixels as flagship-class phones with state-of-the-art hardware and software. They also priced them accordingly, making them expensive as an iPhone and justifying the price point with the exclusivity of a Google product.
At this point, it is clear that in five years Google has not developed the maturity and expertise required to deliver a flagship device: the only possible recommendation is to avoid purchasing a Google Pixel unless you are willing to accept a phone that is defective by design.