Innovation is driven by some utopian end game, a picture of what could be in the future. It has to be far out enough that is still teases the imagination and remains plausible.
Too Far Out
If it is too far out it becomes too much of a pie in the sky. It could become reality someday, but most people will not buy in. It is projected at infiniti.
Too Close By
But when that picture of the end game is too close by, it feels top easy. An iteration. Anybody could achieve that. It does not inspire action. It is projected at tomorrow.
So how do you decide which time span is right then? Not topfar out, not too close by? That depends. Mostly on your industry and audience. It takes practice and a number of tries to iterate it to a time span that works. As a starting point, take a five or ten year outlook and work from there.
Noticed how few initiatives still use the old 2020 suffix? Most of those have been replaced by 2030 now.