I did some digging around in the console, and there's definitely an indexing bug on some devices, including my 14 Pro.
At first I thought maybe it's taking a really long time to index my photos, music, or mail because those are the apps that have the most data - thousands of photos, songs and emails.
So I went into Settings > Search and disabled spotlight indexing for those apps, and then rebooted the phone. But the indexing message persisted.
Then I figured, why not search for errors related to Spotlight in the Console app. And I found this:
View attachment 2640036
and this:
View attachment 2640037
Now, pardon my lack of expertise in the internals of the iOS operating system, so I consulted Gemini, and this is what it said:
Essentially, those of us stuck at the same indexing percentage should just wait for beta 2 and hope it gets fixed.