I’m pretty sure there was research done that showed that people who are hypothetically transported back in time, won’t be able to make any meaningful contributions to the era they go to. They will just end up integrating in that the society of that era.

Basically if you go back in time to medieval Europe, you could introduce something like paperclips to society, but you won’t be able to introduce things like computers even if you know how they work and how to use them.