it's a market system
Exactly. And in a market system those who grow, manufacture, produce, extract or otherwise supply something that others want are often in a stronger position than those who want it
Assuming there's not an oversupply which in this case there isn't.
Pretty much anyone who can be bothered to get up early would quickly learn how to farm
This is true, however not that many people want to.
A small ten hectare farm can't support that many people (and there are smallholdings even smaller than that in Poland, down to 3 hectares) leading to a skills/labour drain from the countryside.
The love affair that the various Polish regimes have us over the past few decades of capitalism has caused that drain and now those who still farm can call the shots.
they are not the only essential workers and they are not protesting peacefully
Peaceful protests sadly achieve little and hopefully other workers will understand their own value and take back some of the ill-gotten gains of the capitalists who have been screwing them over with glee for so long.