Welcome to post-peak iPhone. It's all downhill from here. The only reason for quicker review times is lower number of submissions. Apple has kept a constant app review team size since the beginning, as they always said they would. There's no other way to spin this fact. Most iOS apps are in "maintenance mode" now. Apple killed innovation by forcing their stupid policies on small developers to drive them out of business (family share, removal of discoverability). Now that the iOS platform "Apps Advantage" is gone due to Apple's own arrogance, iPhone market share is now on a downward trend as iPhone becomes just another smart phone. Cheaper will always win without a significant differentiation to justify higher cost.
In the beginning of the App Store, Apple put developer partners FIRST with attractive policies and a robust development environment because they needed to attract apps to the platform. As soon as they idiotically believed they were on top, they threw partners under the bus with draconian policy changes. Now the bus is out of innovation 'gas' because the cost and risk of bringing a new idea to the platform is now to high. ka-flush.