But at the current time I feel CloudFlare has more reputational skin in the game, that they're merely selling off spare capacity as opposed to making a separate business model work, and they don't offer logging as a service although they can certainly break their promises at a reputational risk.

In time NextDNS can build up their reputation perhaps to a point even exceeding CloudFlare, but right now I feel those who are joining early are "paving the way" via risk to their privacy.