Some of the worst we saw on the left was definitely worse considering there were fires that wiped out many businesses. However there was definitely malicious property damage by some, and there are even reports of some pipe bombs or some type of explosive device. I think one difference is that this was the capitol, the symbol and headquarters of the country so of course it gets a different level of attention. We have had many riots over the years, when was the last time our capitol was entered in this way?
I think the important thing to remember is that just like BLM protests, many (most?) there were not violent. The BLM protest and the protest on the 6th actually share a number of things in common. Both sides believe they were there for a just cause, they both had passion and thought they were standing up for justice. They were both wrong in their beliefs and their protests got out of hand.
I also think Trump is morally culpable (but probably not legally culpable) for what happened. This is just another in his long string of failures as a leader. That said I think the left is also somewhat to blame. They excused or minimized protests on the left for so long. These guys can't help but think they should be able to get away with this after ANTIFA could seize a police station and a city block.