It was plan B if the FIBs in the crowd, the crapitol police, and their antifa allies didn’t have luck stirring up violence and panic in the main crowd. No doubt the FIBs would have detonated those to fram Trump and Trump supporters. Bonus points if they could have done it when Kamala or Pence were at the respective locations.
it was about the timing
they couldnt count on riling up the crowd at a certain time
the certification hearing had to be interrupted before any challenges were made
and along come the pipe bombs found at exactly at the beginning of the certification hearing requiring the clearing of the capitol
when the certification hearing was reconvened it was under emergency procedures
no challenges allowed
there is your coup