Leaving aside that older people aren't as enthused about FT work they've known for 30 years, many of them keep jobs or get bored and lonely without them. Not everyone wants to sit around crafting useless projects, or consuming. Creating value for others and connecting (and status signaling) can provide meaning, and granted in retirement there are other vectors for that made available such as volunteering.

It's not a good argument against UBI, but there are better arguments against UBI.

I think volunteering could actually solve part of that. Butarge scale of volunteering work, thinking about the scale of unemployment in the future, might need governments to step in to create them.

You don't have to make a binary choice between work and useless craft projects. Community projects and helping other people in their more meaningful projects can be useful and be fulfilling and make someone feel accomplished. Part of the problem with working as much as possible until retirement age is you never build any community presence or report and don't often make friends doing their own projects that would need your help.