"Lockdown Mode" on your Mac, iPhone and iPad does various things including reducing some vulnerable functionality in webkit.
Apple presents Lockdown Mode as best for rare individuals with extreme security needs, but I tried Lockdown Mode on my Mac and iPhone for about 3 months and found it wasn't very cumbersome, nothing like I expected.
I tested it because I have to recommend security measures to various people.
The only annoying part was receiving text messages with links. I had to copy/paste links from Messages into a browser (not Safari, btw).
There also was an app that warned about some reduced features in Lockdown Mode, but after I closed the warning I didn't notice any problems and forgot what app that was.
If you don't like Lockdown Mode, it's easy to turn it off. It's easy to turn it back on. Then off again. Consider trying it.
Here's an article that includes info on Lockdown mode and webkit:
About Lockdown Mode - Apple Support
"How to exclude apps or websites from Lockdown Mode"
"While your device is in Lockdown Mode, you can exclude an app or website in Safari from being impacted and limited by WebKit restrictions. Exclude only trusted apps or websites and only if necessary."
Here's a Sept 23rd, 2023 article at webkit.org about Apple's Lockdown Mode:
https://webkit.org/blog/14445/webkit-features-in-safari-17-0/
"Lockdown mode now:
"Disables IndexedDB.
"Disables the File API and FileReader API.
"Disables support for the <embed> element.
"Disables the Web Speech (Speech Synthesis) API.
"Disables the WebLocks API.
"Disables support for experimental APIs.
"Supports select web fonts.
"Lockdown Mode is also now supported in WebKit on watchOS.
