No it was not an insurrection. IT WAS AN ATTEMPTED INSURRECTION. Even the Proud Boys blamed the violence on trump. trump called for it, he asked the to "fight like Hell." Then he watched with glee while his cult beat police, trashed the Capitol, and threatened the lives of mutiple elected officials and staff.
The J6 Committee took testimony from trump assoicates and other repubs who told the world what the MAGA cult did. They tried to stop the certification of a duly and fairly elected President. That is an Insurrection attempt. It failed. If it had not, we would now be an Authoritarian, in the likes of Russia, China, and North Korea.