I recently read that, only about 70 of the top 500 companies of the 1950s are still around today; businesses that must have seemed rock-solid to investors back then went the way of the dinosaurs.
The market changes all the time. It’s nearly impossible to predict the needs and competitive landscape of tomorrow. In spite of the best unfair advantage, an unforeseen change in technology might mean completely new competitive dynamics (think Apple vs Nokia).
There’s many positioning and competitive advantages a business can have. Some might change, some won’t.
Focus on the things that don’t change (Jason Fried).
Everything might change around your core offering but, some desires are there to stay. People will always want faster, more reliable, better customer service, etc. Focus on what won’t change.