Unearthed Arcana is unofficial material that is available for playtesting purposes. UA subclasses make it into sourcebooks like Xanathar's Guide to Everything generally after being refined from playtest feedback and then made official.
The simple answer is because Unearthed Arcana in not a source book.
I do think there should be someplace that lists all the active playtest content on DDB though. I made a request thread here and am (with some latency) keeping the list up to date.
UA is definitely a source for interesting and valuable material you can use in your adventures! Also it's "unofficial playtest content," meaning that Wizards of the Coast uses it to detect and iron out the kinks in their ideas. Use it in your campaigns like you would use homebrew or DMsGuild content - as much as you'd like! But also don't be surprised if it's not completely balanced or if you find some unexpected contradictions of rules.
But I totally agree it would be really cool to see a compilation of all the UA content that hasn't been canonized. :)
Why is not UA in a sourcebook. Would be nice to see only the UA stuff together !!!
Xanathars had a bunch of UA stuff in it
Unearthed Arcana is unofficial material that is available for playtesting purposes. UA subclasses make it into sourcebooks like Xanathar's Guide to Everything generally after being refined from playtest feedback and then made official.
The simple answer is because Unearthed Arcana in not a source book.
I do think there should be someplace that lists all the active playtest content on DDB though. I made a request thread here and am (with some latency) keeping the list up to date.
UA is definitely a source for interesting and valuable material you can use in your adventures! Also it's "unofficial playtest content," meaning that Wizards of the Coast uses it to detect and iron out the kinks in their ideas. Use it in your campaigns like you would use homebrew or DMsGuild content - as much as you'd like! But also don't be surprised if it's not completely balanced or if you find some unexpected contradictions of rules.
But I totally agree it would be really cool to see a compilation of all the UA content that hasn't been canonized. :)
Edit: Ta-da. I made one. https://www.dndbeyond.com/forums/dungeons-dragons-discussion/unearthed-arcana/49503-repository-of-unearthed-arcana-content