If some mad gazillionaire decided to start paying people to hit their own thumbs with hammers, I'm sure she could find a price point where a lot of people decided they wanted to do that. If she kept doing it for long enough, self-hammer-mangler might even become an honorable profession to which a lot of people aspired. That doesn't imply that we, as a society, want people to be spending their time and energy hitting themselves with hammers.
As a society, we spent the last few centuries having the problem of providing a comfortable standard of living to ourselves and our peers and the problem of getting shitty drudgework done be two problems that largely solved each other. We are well on our way to actually solving the shitty drudgework problem. That means we badly need to find a new solution to the comfortable standard of living problem, but deciding not to fix the other, fixable problem doesn't sound like a viable long-term strategy.
In the US, grocery worker jobs are some of the only blue-collar jobs left that still provide a middle-class income with benefits. There are lots of people for whom getting one of these jobs is something to aspire towards, not some terrible fate to dread.
This has a lot to do with the fact that grocery workers are better unionized that most -- 19% of workers in the retail grocery industry are union members, compared to less than 7% in the private sector overall (source: https://www.gc.cuny.edu/CUNY_GC/media/CUNY-Graduate-Center/P...). Which is one of the reasons for the push towards self-checkout; it pushes those numbers down, which reduces the bargaining power the union can wield on behalf of those workers who the machines don't replace.