I think it’s fine to seek and secure labour, materials and funds from fans during particularly difficult times, but it isn’t sustainable long term. Sponsorship is different of course as is contributing to gain a collective say in the running of the club in a fan owned model.
Generally agree but I’d also question, what is really sustainable? Sponsorships need sourcing and renewing, new investors are only as sustainable as long as they’re interested and around. Volunteer and gift in kind support is perhaps more sustainable, if the good will continues. Just playing devil’s advocate.