Everything reduces to specific people acting on their a priori motivations in bounded contexts, and any system of centralized control is guaranteed to enable expressions of the worst motivations of the people involved. The distinctions you're making -- "private" vs. "public", "corporations" vs. "governments", etc. -- are fundamentally meaningless.
There are no "democratic norms", just norms adhered to by specific people and the factions they form, contesting against each other for power over others. Performative "democracy" is often just cover to allow the currently dominant factions to function as "dictatorships".
Decentralization and individual autonomy are the only solution to the problems you rightly care about, but what you're proposing is literally the opposite of that.
Maybe if Cloudflare had workplace democracy my concerns would be different, but they don't and wield too much power.
If it also helps I also think 99.99% of big tech should be broken up into separate, probably a few 100, different companies.
So yes, anything vital for the internet should be controlled by the people through democratic norms, institutions, and values rather than dictatorships by those with money over those with none.