This is a common meme but wrong.
The imported goods are subject to the same restrictions as those produced within EU.
What hurts EU farmers the most is the big supermarket cartel that controls prices and pushes farmers to produce more and more cheaply (and consumers that react extremely sensitive to every price increase, but that’s a more inconvenient truth)
Definition of a cartel is a combination of independent commercial or industrial enterprises designed to limit competition or fix prices - it can be a cartel that basically oppresses farmers and have low consumer prices as result
What hurts EU farmers the most is the big supermarket cartel that controls prices and pushes farmers to produce more and more cheaply (and consumers that react extremely sensitive to every price increase, but that’s a more inconvenient truth)