That was the case in 2020, now in 2025 leftism is dying.
To clarify; many members of the leadership of the Golden Dawn were involved in criminal actions. Certain members of the party ordered attacks on immigrants and promoted violence in many ways. They were a typical "Neo-nazi" organisation with no serious spiritual foundation.
While they said many truths, especially Kasidiaris, who now has his own party, their stupidity held them down and limited their potential. They were the third largest party in 2015, but their increasing involvement in crime and their lack of proper arguments made them unpopular. Instead of devising a political plan and being diplomatic, they focused on organising marches and preaching about retaking Constantinople (Istanbul).
They gave the jewish media the opportunity to bash on National Socialism and equate it with gang violence.
The name "Golden Dawn" stems from their belief that Hitler was a follower of the Hermetic Order of the Golden Dawn, which is false. Overall, the Golden Dawn did say many truths, exposing jews and freemasons, openly denying the holohoax, and refusing to sell Greece to jewish banks, but their behaviour was non-Zevist in many ways. I don't believe they were controlled opposition, they were just stupid and unspiritual. Their ultra-nationalist christian beliefs and their emphasis on being "macho" made them lose credibility.
It was good that there was some opposition, but it shot itself on the foot. The anarchists and leftists were happy to see the Golden Dawn in prison, but patriotism/nationalism is rising rapidly once again, this time in a healthier manner.