> We invent machines to free ourselves from labour
That's a very romantic view.
The development, production and use of machines to replace labour is driven by employers to produce more efficiently, to gain an edge and make more money.
Average hours worked is more or less monotonically decreasing since the start of the industrial revolution, so in the long run we are slowly freeing ourselves. But in the short run, people keep working because a) machines usually are complementary to labour (there are still coal miners today, they are just way more productive) and b) even if some jobs are completely eliminated by machines (ice making, for example), that only "solves" that narrow field. The ice farmers can (and did) reenter the labour market and find something else to do.
Because we invent machines not to free ourselves from labor (inventing machines is a huge amount of labor by itself), but to overcome the greed of the workers.
