The machine increases the exploitation of the worker by reducing the amount of labor hours it takes to make a thing.

For a simple example suppose holes in the ground have a value, if a capitalist pays a worker to dig holes and the worker can dig 1 hole an hour with a shovel but 2 with an excavator then while paying for the same 1 hour of work the worker will create twice the value for the capitalist.

But really the distinction is mostly semantic and it doesn't matter much whether Marx was right and the machines create no value or some other economists were right and it takes machines/tools as well as labor to create value hardly matter because either way the capitalist brings nothing to the table.

its a simplified example, where the boss of the worker can barely break even and depends on the surplus he gets from waged labor to make a profit, machines let the worker make more product in less time, which means, for less wage and gives him more surplus

in the case the machinery would let the worker make 100 chairs for 1g instead of 2, then the exchange value for 100 chairs would go from 950g to 901g and the time to produce them would go from 50 days to just 1

EDIT: if the change of machinery is sudden then the boss can get away with still selling 2 chairs for 19g and have 49g as surplus a DAY, until market pressures take his surplus away

if the worker was eliminated you could cut time shorter and shorter but not reduce cost through wage labor, and in a saturated market competition would barely let you break even

They're good for us as consumers as they make things cheaper and they're good for socialism as they reduce the amount of labor needed overall. As for the price (price being different than value), it lags behind a little bit. When the machine turns 5G of materials into 5G of product, the price may still be 7G for a time. But eventually it stabilises towards its actual exchange value. It'll go down to 6G, then 5G as capitalists try to find an angle to sell more of their products. Then a better machine needs only 4G of material to make one item and the cycle repeats.

This assumes the machine does everything with 0 human labor which even today doesn't exist, even automated machines need someone to calibrate them the first time around. The worker is paid 1G per day no matter how much he produces so less expensive machines that process 4G of raw materials instead of 5G are still interesting. 5 products in a day at 5G means you pay 26G (5x5 + 1 in salary). 5 products at 4G means expenses of 21G, 4G suddenly appeared as profit because the worker is still only being paid 1G for his day of work.

edit: and I forgot to take into account that the machine loses a bit of value every time it creates a commodity since it suffers wear and tear. It transfers some of its value to the item, but doesn't create any - not like a human that can survive on 1G a day and come back to work the next day to produce 2 or more chairs.