Nah AGT and Picard don’t happen in the same timeline. AGT was some sort of alternate timeline. But the events of the Prime timeline diverge enough from the AGT timeline that it makes more sense that the new warp scale was unique to the AGT timeline and didn’t happen in the Prime.
And then back for Picard when the max sustainable is warp 9.99.
Nah AGT and Picard don’t happen in the same timeline. AGT was some sort of alternate timeline. But the events of the Prime timeline diverge enough from the AGT timeline that it makes more sense that the new warp scale was unique to the AGT timeline and didn’t happen in the Prime.
They certainly exist separate of each other. That we all have to call into question the timelines is half the fun.
Concerning times they exceeded warp 10 in TOS:
The narrative awareness and scaling has changed over time. I imagine largely due to people like us.