did the particle accelerator really create Flash?

This has been bugging me for a while now in Thawne's original timeline he said Wells successfully activated his accelerator in 2020, meaning no explosion so how could it have given Barry his powers? Plus if we assume that it did, then Flash would only have been active for 4 years before he disappears in the crisis, not a very long time to have a long-standing rivalry with Thawne and train and master his abilities to the point where he can control jumping through time.

I believe that in the other timeline the lightning still struck Barry, it's his destiny to be the Flash Thawne moved up the accelerator's construction solely to give himself a way into Barry's life