GoodTask or OmniFocus are good one-time paid options, I’m certain they would have family sharing and they allow file attachments, pretty much anything you would ever need. If its not, there are millions of workarounds and they seem quite actively developed
Stay away from subscriptions, history repeats and rhymes
Keep some tasks as LISTs that you never “complete” but you can all add to and modify as you notice things running out or refilling or ongoing tasks or any other system aspect that needs to be kept up to date. Honor system heh