CBS Evening News at one time, we can collectively agree, was the ratings juggernaut back during the days of Walter Cronkite. Cronkite's most notable competition was The Huntley-Brinkley Report, co-hosted by Chet Huntley and David Brinkley, and that program would be renamed to what we know today as NBC Nightly News. ABC Evening News became ABC World News Tonight when Roone Arledge was brought in to give ABC a major ratings turnaround.
After Cronkite left CBS in 1981, it seems that CBS gave up on being competitive against ABC and NBC, as evidenced by CBS Evening News remaining stuck in last place behind ABC World News Tonight and NBC Nightly News, as well as CBS Mornings (also carried names like CBS Early Show and CBS This Morning, which CBS has struggled to make up its mind with a long-term morning show branding) remaining stuck in last place behind ABC Good Morning America and NBC Today. Although CBS had a notable exception during the 1998-99 period when CTM had a short-lived ratings surge and GMA had the pairing of Lisa McRee and Kevin Newman that proved to be a ratings disaster, and management at CBS seeming to also embrace the "status quo" and "lack of patience" mindsets. I'd hope CBS management would break free of those mindsets, and embrace giving Tony Dokoupil time to prove himself.