I'm sorry if it landed harsh. First, I don't think not knowing things is inherently bad or shameful--it's where learning starts, etc. Second, there's a misunderstanding here, whoever is expressing it: decentralization at the level of a protocol--ActivityPub or w/e else--is NOT the same thing as decentralization of infra. People running mastodon instances, or Matrix servers, or other fedi systems, are also in most cases leasing infrastructure from hyperscalers to do so.