The Google Pixel 5 may actually be the US$699 successor to the Pixel 4 XL, not the Pixel 4
Google is rumoured to be launching the Pixel 5 in October, but it may not be a successor to the Pixel 4 in the truest meaning of the word. According to @ImjustSayingJC, who has been quoted by ITHome and Gizchina among other outlets, the Pixel 5 will only be available as an XL device. If this information holds, then the Pixel 5 would be more of a successor to the Pixel 4 XL than it would be to the Pixel 4.
However, the Pixel 4 XL may well be more powerful than the Pixel 5. According to "information that they have been provided", @ImjustSayingJC adds that Google will pair the Pixel 5 with a Snapdragon 765G, which correlates with previous rumours about the device. Based on our database, this would put the Pixel 5 at a performance deficit of around 18% compared to the Pixel 4 XL.
Additionally, @ImjustSayingJC reaffirmed the rumour that Google would be returning to a capacitive fingerprint scanner for the Pixel 5. Hence, the Pixel 4 XL would have a more advanced method of biometric authentication, along with Soli radar functionality. This reduced feature set apparently corresponds to a lower starting price, though. According to the same leaker, Google will price the Pixel 5 at US$699.
The one area that the Pixel 5 may have over the Pixel 4 XL is its display refresh rate. According to Ross Young of Display Supply Chain Consultants, Google will release a device with a 120 Hz-capable display this year. The only device that Google has teased so far is the Pixel 4a (5G), so it would seem unlikely that this would receive a 120 Hz display over the Pixel 5. Young also stated that the 120 Hz display would have a resolution of 6.67-inches.