I'm familiar with that perspective, and biased towards it... Cloudflare is certainly in such a position, but they are a relatively young company (for their size and reach) and I've seen good things come from them.

I'd guess the intent is unlikely to be anti-competitive or monopolistic, just over-aggressive. However regardless of intent their position does cause an absence of market forces to put pressure on fixing such issues - Similar to how it's become acceptable to have downtime when it's on AWS, because "everyone is affected".