Awareness. Without this then making the right choice is hit or miss.
For backup (and security, for that matter) it is analogous to insurance: how much do you want to pay vs how painful if there's not enough. And the only person that can decide how much is enough is the the person who's data it is ... provided they can make an informed decision.
For certain: some backup is significantly better than no backup!
@NAS Newbie I don't know how much critical data you have (irreplaceable family photos; work files) but you might consider using the Synology C2 Backup for off-site backup if the dataset is small enough (Plan 1, <1TB live data, includes daily versions for 30 days; Plan 2, >1TB live and versioned data). I use it for photos etc. and can survive if everything else on local backup is lost though it would be painful. If you do have a very small uplink speed (like my 6Mbps) then it can swamp it and take a long time but there are bandwidth settings in DSM and SRM that can be applied to keep your family happy.