I'm wondering if there is something wrong with my submission. It looks normal. For the same app, prior reviews took two or three days.
Waiting for review for 10 days
Same situation here, first submission with two subscriptions attached, sitting in "Ready for Review" since July 24 with no reviewer assigned and nothing in the History log since. Opened a support case with Apple Developer Support (App Review Status) on the 29th, got the automated acknowledgment, no human reply yet. Posted my own thread on this too, seems like a lot of us are hitting this at the same time this week, might be a wider backlog rather than anything specific to one submission. Have you opened a support case yet, or heard anything back?