In the past this wasn’t true, but it’s definitely true for new tech products.

There are 2 reasons for that, IMO.

1. Tech investors expect year after year, decade after decade of serious growth
2. Tech these days is not something you buy, it’s rarely even something you rent, it’s often free and paid for by shoving ads at you

That means that they can’t just land on a good product and stick with it. They have to keep changing it to try to get more engagement, more use, more growth.