This is impossible, sorry. blockchain is before anything else, a very opinonated implementation of applied economic theory. The technology is secondary and consequent to the belief that people as a whole cannot be trusted to take care of things that they do not pay for. I say this is someone who is far from a fan of blockchain anything, but there's no getting around the fact that it is impossible to divorce it from its core principle, which is that pay to play has to be baked into the system at its deepest foundation.

And as soon as you introduce this, pay for the many becomes profit for the few, and inevitably markets, trading, and rent-seeking cartels form who swiftly capture the natural value confluence points of the system, reversing any decentralizing tendencies it may have, and collapsing it back towards centralization in order to consolidate and protect their advantaged position.

If all your target users are comfortable with the tradeoffs of systems built on blockchains (ie private key is the source of authority), you're probably looking for Nostr.