The longer fork represents the consensus of the network, as it has accumulated more computational work and has a greater number of participants supporting it.
Being the longer chain does not mean a fork has accumulated more computational work. Proof of work is determined by the difficulty in solving the puzzles which influences the amount of computational energy that is spent. A longer chain can have significantly less computational work if it has a low difficulty level.
Considering that both chains are supposed to exist at the same time, and having forked apart from a common block, how would the longer chain have a lower difficulty level if both chains adhered the difficulty retargeting protocol?