Calling someone a shill is a basic accusation.
If you cannot refute their argument and resort to ad hominem, it only highlights your lack of insight.
Basically, it is the same tactic employed by the bias leftist media which refuses discussion in lieu of character assassination and defamation.
If one's actual objective was the educate the reader or viewer a clear counter narrative back with actual events and statistic would show more weight, instead people are constantly bombarded with an excess of information designed to deemed the other side's opinion or stance invalid through associations of guilt and poor judgement.
If you find yourself going back and forth calling one another a shill as the prime objective in your discussion or argument, then there is no substance to be had.
It becomes a system of derailment and no intellectual compromise is reached.