it's unobvious for me, why quantum entanglement is considered to be active link
Let's walk through a particular variant of the EPR paradoxon. You probably already know this, but I don't know how to explain the problem any other way:
Consider a source that produces entangled photon pairs polarized in z-direction with net spin 0, and two physicists Alice and Bob making measurements.
Alice always measures the spin component of her photon in x-direction, whereas Bob may measure the spin component of his photon in either x- or y-direction.
Let's assume that the source, Alice and Bob are at rest relative to the lab frame, but Bob is closer to the source and makes his measurement first. If Bob takes a measurement in y-direction, Alice' measurements will be uncorrelated. If Bob takes a measurement in x-direction (corrected), results will be correlated: Alice will always measure the opposite spin.
This is paradoxical if you assume wave function collapse is real and local, however is happens (magic, decoherence, stochastic interactions or whatever else floats your boat).
Somehow, Bob's photon needs to tell its partner that it can do whatever it wants if the measurement was taken in y-direction, but force it to do the right thing if the measurement was taken in x-direction. This information needs to propagate faster-than-light so it's available before Alice makes her measurement.
There are several possible ways out of this situation, and I'll list three of them:
First, you can posit that there never was a collapse, that we're just dealing with statistical correlation and the paradox is a result of applying classical intuition to quantum systems.
Second, you can posit that the spooky action at a distance is time-symmetric, ie both Alice' and Bob's measurement will send information slower-than-light but backwards in time until it reaches the event that created the entanglement, which in turn sends information forwards in time. The photons will always have known what spin they'll need to end up with. The pseudo-time I used in my explanation is only a didactic tool: The physical process is atemporal interference across space-time.
Third, you can accept that there are indeed faster-than-light interactions, which, however, cannot be used to transmit information - they are an internal bookkeeping mechanism that keeps the universe in sync. The same thing happens in quantum field theory, which is explicit if you use the virtual particle picture, but even without it there are correlations between field excitations across space-like separation.