This is a business decision, as the Bengals are saving money in the running backs room. The Bengals were first in the NFL in cap space going to running backs, which is a position that many deem to be less valuable than others.
By cutting Bernard, the Bengals are saving $4.1 million in cap space. The Bengals recently re-signed Samaje Perine to two-year, $3.3 million deal. This means in 2021, the Bengals will save about $2 million in cap space for their RB2.