This is the first phone running a Google chipset, and Google CPU. And a Google modem I believe. Their previous phones were Qualcomm based. I imagine a lot of the issues people are seeing are related to that, a mix of hardware flaws and driver bugs.
Isn’t the “Google CPU” just rebranded Exynos? In which is case it’s almost always worse than same generation Qualcomm in performance. One of the reasons why I couldn’t stomach purchasing a Samsung phone here in Europe was that their Exynos processor was worse across the board than what the North American benchmarks on YouTube would have you believe.