Honestly, I wonder the same thing about the Time Lords themselves. Why doesn't he run into them constantly
? Sure, they were 'time locked' (whatever that means), but their exploits before the Time War already happened. Their impact on the universe already happened. The Doctor even talks about said exploits every now and again, such as with the Corsair. And then you have cases where Time Lords such as the Meddling Monk influenced Earth's own history; construction of Stonehenge, 'suggesting' aircraft design to da Vinci, etc.
I mean, is being time locked just shorthand for 'erased from existence?' Because that's the only way it would make any sense. But we already know that's not the case.
Sure, no bumping into any Time Lords who are aware of events post-Time War. That much makes sense. But none at all? Not so much.