This indeed causes problems when wanting to create a quick ad-hoc group for a party invitation etc., if at least one of the invitees is not an iPhone user.
> Creation of invitations requires an iCloud+ subscription.
This isn't about making life easier on people, this is about getting you to subscribe to Apple's services for access to a REST API. Apple gets some benefit of the doubt, but this is literally Slop-as-a-Service.
> Do invitees need to have an Apple device with the app to attend an event?
> Apple Invites is for everyone. Guests don’t need the app, an Apple device, or an account to RSVP to an event.
Source: www.icloud.com/invites
Right, so how do they get and respond to the invite? I'm guessing SMS or email, making the whole thing pointless.