If you automate everything, how is profit made? Say every firm charges a 5% markup above costs of materials and machine upkeep. A given firm must pay other firms' 5% markups on the materials it needs, making it cheaper for the firm to produce those materials itself. This tends toward complete centralization. There are two ways to fix this. The first is to have an economy based on many monopolies trading resources. This obviously suboptimal for economic calculation. The second way is to adopt a planned economy.

As labor productivity increases, profitability decreases, as historical data shows[1]. In the long term, this problem of capitalism cannot be avoided.

[1]: https://thenextrecession.wordpress.com/2022/01/22/a-world-ra...