The biggest advantage of guitar tabs is you don't need to be able to read music. You just need to know how to count. The timing is a non issue as most people will try and learn the song with a tab and a recording of the song.
Which is funny if you presume it is true that tabs precede standard notation (and therefore recording techniques).
Tabs make quite a bit of sense in a post recorded music culture. However, the information density you can get in standard sheet notation is far greater. There's tradeoffs.
For most people using tabs, the additional information is not needed as you are most of the time not aiming for an identical replica of the song. You might play it slower or faster, different key, remove sections, etc
On the other hand I think tabs actually do strive to be an actual replica of a song. That's why there are so many versions of the same tab that broadly sound the same, from people trying to get as close as they can by ear to the recording.
Powertabs or guitar pro files fix the tradeoffs at least. You get the sheet music for all instruments, tab, and midi instrument backing tracks to listen to in one view. And a metronome.
