I wouldn't say many because we can probably count them on our fingers. I personally don't feel so concerned about that sector though because it's a capital intensive industry. My take is that monopolies in such industries are not as harmful as monopolies in other industries which have naturally low capital barriers where the anti-competitive forces are felt far more strongly by more market participants.
When capital barriers are low and you are able to build a product which solves a problem 10x better than the competition within a specific niche, it comes as quite a shock when you cannot even find a single user willing to try your product for free. A product which is low capital to build can be very high capital to sell because you need an enormous marketing budget to even get one real user to try your product long enough to realize that it's 10x more efficient than what they're using now. Then there might be a ton of additional regulatory barriers standing in the way of a sale (esp. B2B). Massive chicken and egg problem. These kinds of situations where sale becomes a total bottleneck and stands in the way of delivering economic efficiency can make one feel that the economic pie must be shrinking fast.
When capital barriers are low and you are able to build a product which solves a problem 10x better than the competition within a specific niche, it comes as quite a shock when you cannot even find a single user willing to try your product for free. A product which is low capital to build can be very high capital to sell because you need an enormous marketing budget to even get one real user to try your product long enough to realize that it's 10x more efficient than what they're using now. Then there might be a ton of additional regulatory barriers standing in the way of a sale (esp. B2B). Massive chicken and egg problem. These kinds of situations where sale becomes a total bottleneck and stands in the way of delivering economic efficiency can make one feel that the economic pie must be shrinking fast.