Also, their organizing rhetoric, i.e. "Stop the Steal," did not imply an attempt to be annoying and temporarily delay the election.
Protests do not stall free elections anyway.
- An election occurs which allocates electoral college delegates for each state
- Those delegates meet and cast their votes for the candidate of their choosing.
- After they vote, each state creates a Certificate of Vote. This is the actual legal document that elects one as president. 6 copies are made: one sent to the VP, one sent to the SoS, two to a US archivist, and two to the chief judge from the closest district court.
- In early January, Congress meets to count the certificates. That is the actual election. Everything before then is just process.
So while the election had occurred, the process was not yet finalized. Until those votes are counted by Congress, then the person elected by the people in November is not elected president. The rioters were absolutely attempting to disrupt the most crucial part of the process -- the thing that legally elected Joe Biden president.