I think you must be thinking in blockchain terms where there are different classes of “users.” In blockchain: there are end users with a wallet or thin client, and miners running full nodes who can make changes.

In holochain, to USE an app, you have to run that app, which makes you a full peer for that app. You have a private key to write to your source chain, and run your little shard of the DHT. So, the more users, the more full peers there are sharing the load. There is no native way for someone to “use” a holochain app without being a full node in that app.

But remember, each holochain app is a separate holochain, you are only carrying your share of that app, not of all apps in some big monolithic blockchain. So it is a light load to carry.

The only theoretical exception I can think of is that some user (full node) might want to provide some kind of read-only web gateway to the public as a service. If you want to call those viewers of app data “users,” then you would be correct that they aren’t carrying their part of the load — the user sharing the web gateway would be carrying that for them. But those viewers would not be able to interact with the system in terms of changing any state (such as submitting transactions), so I don’t really consider them to be users just spectators.