Did the performance of your iPhone take a huge hit when you installed iOS 14.5.1? Well, the issue was so bad that Apple noticed, and has released a fix.
The iPhone 11 was particularly affected, with performance so bad that older budget iPhone XR could outperform it. This problem was clearly highlighted in a benchmark video released by Nick Ackerman.
With the release of iOS 14.6, Ackerman decided it was time for a rematch.
The scores speak for themselves, especially the Geekbench scores which are now where we would expect them to be.
Whatever throttling that was going on in iOS 14.5.1 is gone in iOS 14.6.
It's unclear what the issue was, but in the release notes for iOS 14.6, Apple did mention that there was a fix for an issue that may cause an iPhone to "experience reduced performance during startup." Whether this was the same issue or a different thing altogether, I don't know.
Either way, the problem seems to be fixed, so if you were affected, it's time to update.
And if this isn't reason enough to get you to drop whatever you're doing and carry out an update, then the more than 30 security fixes contained in iOS 14.6 should be.