But update I did, and it wasn’t long before I regretted it. Here’s a brief rundown of the problems I’m seeing:

Reduced battery lifeApple becoming sluggish and temporarily unresponsiveConnection to Apple Watch has become somewhat unreliableScreen becoming unresponsive to touch (locking and unlocking seems to fix this)

Yes, I’ve rebooted. Yes, I’ve given the handset enough time to index things and recalibrate the battery. Yes, I’ve updated all the apps.
It’s clearly an iOS 15.2 issue.
On the plus side, it seems I’m not alone in having problems. Other iPhone owners are voicing the exact same problems on social media and on Apple’s support forums. 
Launching new features and security updates at the same time results in problems, which in turn makes people’s fears of running into issues stop them from upgrading.
Is there a fix for these issues?
Not that I’ve found. I’ve tried a number of things, and it seems that the fix will have to come in the form of an iOS 15.2.1 update.
Are you seeing problems with iOS 15.2? Let me know in the comments below.