I think you're missing the point. He was right in not wanting to create a panic, but he downplayed it so much that people didn't think (and still don't) they needed to take COVID seriously. All he had to do was tell people at the very start of all this was to wear a mask, listen to your local authorities and do everything you can to reasonably social distance (until the actual lockdowns happened).
Trump didn't downplay it so much people didn't think they needed to take it seriously. The media caricature of Trump did.
Trump says that Democratic claims he's doing nothing are a hoax. Media reports Trump calls the virus a hoax.
Trump says it's like the flu and the flu is dangerous and kills people. Media reports that Trump didn't know the flu kills people.
Doctors use hydroxychloroquine and Bayer donates a ton of it, then Trump mentions it. Media reports it's dangerous and deadly.
And while there's this concerted effort to make Trump look as wrong as possible, there's also constant fear mongering. Constantly coming up with new angles to terrify people. Like the stupid one the other week where they reported some kids having a greater infection than adults as kids being more infectious, not accounting for the study only dealing with people who were in the hospital for treatment. The logical error is so clear, they may as well replace the old WWII plane example when teaching about survivor bias. How can we hold Trump to task on his communication when entire communication industries dedicate themselves to undermining the messaging?
Like, at one point he did an interview and was asked if people were wearing masks just to spite him. He said "no, not at all". So they asked a second time if it was possible, and he said something like "well maybe it's possible, but I really think they do it because..." I forget the exact phrasing, and the original interview is behind a paywall. The point is, he was asked the question specifically, specifically said no, and by the time it got to the general public the headline was:
President Donald Trump said some Americans might wear face masks not as a way to prevent the spread of coronavirus but as a way to signal disapproval of him.
www.cnbc.com
Or at a press conference, he asks the doctors that advise him if you could use disinfectant on people's lungs. It's a stupid question, I agree entirely it's a stupid question, but it's so easy to say "no" to that stupid question. It was obviously phrased as a question, it came with the explicit caveat that he'd have to see what doctors say, and it was stated in vague terms that you need to translate before doing something dangerous. Top of Twitter?
People barely listen to Trump. It's not coincidence that when he was doing regular briefings on the pandemic personally, his approval was up. More people than average were listening to his actual words, and not the ones invented to make him look bad. Trump at his words is a perfectly medium president doing basically what any other president would do. The danger to society that says all the wrong things is fictitious Trump.