Let’s assume a single person donated all the money that was needed.
Tough luck for anyone else wanting to contribute, and see the print?
If that would happen, lucky for everyone! My assumptions: it’s not just one movie we want to have, right? If anyone contribute to a next project, they’ll get access to the old ones as well.
In your unrealistic scenario all the other donators would need to give just a smaller amount of money to get realized an access to a film. And projects in this forum get a wider release anyway sooner or later, it might happen that in this case, open access would be possible earlier than usually.
In a realistic scenario it looks like this: it is a long run to get the money together, even if there are generous donators, not only the buying of a print, scanning costs and cargo, initiators needs to have lots of terabyte of stationery storage, a high-end computer and screens to manage all the work, and do need time.
All in all, donations always helps, even small amounts. If anybody has another realistic and sustainable way of realizing to scan films, please let me now;)