Marx famously described a varied world of work, which he viewed as a better one:
to hunt in the morning, fish in the afternoon, rear cattle in the evening, criticise after dinner, just as I have a mind, without ever becoming hunter, fisherman, herdsman or critic.
Occupations are helpful identifiers - they are a (relatively) constrained set of options to slot people in to. I rarely think of the people I know best in terms of their careers, but for people I don’t know as well its a handy shorthand. This is true in our broad constructs too: a large number of government forms and other applications require listing an occupation, and usually a single one.
The source of your living seems an important part of your social identity and social worth. This hasn’t always been true - at various points intellectual or artistic pursuits have been seen as markers of status, with simple production relegated to a less distinguished role. Even those feel enveloped by work these days though - you would describe someone as an artist, whether or not they made money from it, and actors are actors even when they’re waiters.
The link between wealth and social status from employment is unclear - a working class job and background can be a strong social status marker. Even when workers are extremely well compensated, status is relative: in Silicon Valley an entrepreneur is more highly regarded than a corporate middle manager, even though they may have similar net-worths at a given point.
Marx’s view that having production allocated by committee obviates the need for a defined occupation, but from the perspective of the individual it doesn’t seem wildly different from the allocation by the market. Where he is right is that defining an identity that transcends specific employment or occupation isn’t something an individual can unilaterally do - its a social construct. Future of work thinkers often discuss the meaning that comes with work, but part of that meaning is expressed through the view society has of us, mediated by our job title. We call someone an entrepreneur when they have started a business, whether or not it succeeds and whatever it does. We don’t have an equivalent word for those that put together a living in several different ways.