Thanks for the info.

If you have to install it, though, developers can't count on it being available to all or even most users.

Neither are legitimate competitors to iCloud

In some instances, nextcloud is better than icloud

You're comparing on-demand-cloud with setup-your-own-server-and-configure-everything-yourself-cloud

Those are two different markets

Only a small fraction of nextcloud users setup their own servers.

Nextcloud has on-demand (if by that you mean a SaaS product)