Thats obvious, more than 50% of projects die within 1 or 2 years. Even the profitable ones come to an end, not to mention the projects made by inexperienced developers aching for fast money. I guess only 5-10% of the projects we see now can survive next 5 years.
I think 5 or 10 percent is kind of excessive, that would mean that blockchain is being practically wasted at all, maybe 20 percent of the projects are promising and well made.