there's always an optimistic take to everything and a pessimistic one. if you're always taking the wait and see approach, chances are you're not going to do anything later, either. be somebody who does things and doesn't just sit around dreaming and waiting (like me)
Just as a couple of concrete examples:
A paid-for app was a great idea in 2009, but a bad idea in 2013.
A dedicated handheld PlayStation was a great idea in 2005 but an awful idea in 2012.
Self-driving car companies were a great idea in 2017, but a bad idea in 2020.
I think the point is that technology changes and sometimes you need to strike whole the iron's hot.
There are so many things that were "before their time" and failed, like garbage-collected programming languages. C beat Lisp, because GC was too slow. Then Java beat C, because manual memory management was too dangerous. Being too early is almost scarier than being too late.
I get that people are concerned about their ideas being stolen, but honestly, you can probably come up with another idea. I think what most people who have their ideas stolen find is that it turned out to not be a good business, and someone else invested 2 years of their life on a painful slog to discover that. On to the next idea!