The result could be as simple as machines just fill in gaps for when were tired, moody or on vacation. We could optimize for min usage of automatons, and target low performers for educational opportunities and psychological support.
The robot is not going to molest my kids and the elderly. The Robot will not cough tuberculosis spores onto them, will not touch their food after picking a nose or wiping an ass (both of which the robot lacks), and will not brush them with herpes sores. When the robot dies, an exact replacement can be had. The robot will never decide to kill out of frustration, religious fervor, or revenge. The robot will not steal.
Today, due to the low amount of money we're willing to spend on care, and the high demands and pressure on the people providing that care, people who care for elderly and sick people often don't have the time for personal contact, often to their own frustration. So let's automate everything else so people have more time for real contact.
':-|
I think his point was that even if you live in a post-scarcity anarcho-communist society where everyone is live and let live, the rest of the universe isn't an occasionally you need headbangers.
Banks himself was distinctly anti-capitalist.
That said, the Culture does seem like it would be a nice place to live, over all.
Take the current political situation in the US. Trump would love for everybody to blindly obey him. His autocratic goals are frustrated by the fact that government is made up of people who are able to resist the government they are part of if they believe it's going wrong. Without those people, Trump could count on the obedience of the literal machinery of government. Having people involved can be an extra layer of protection against abuse.
The reality is that a lot of people already are doing the equivalent of receiving their basic income in exchange for digging and then filling in a big hole.
But maybe there's a cheaper way to meet people's "need to be needed" that's less wasteful of resources. Sports? Video game competitions? Intellectual debate? Volunteer work? There are a lot of possibilities here. I'd love to find out.
In any case, I think it would be prudent to separate the debate about how people get most of their incomes from the debate about how people find meaning in their lives. Tying the two together is only one option and I'm not sure it's the right one.
Long-term unemployed people whose cost of living is subsidized (in the US due to various legal quirks this is mainly disability) are generally substantially less happy than employed people. I don't have studies to hand but would you dispute that result?
Get a pet.