I mean, we’ve seen a number of ships in Starfleet that don’t look identical. The set design also seemed pretty spaceshippy to me. Especially when you consider that it’s an experimental ship designed for this one purpose. Very clean and pristine and showing that one purpose design.

Discovery’s set design resonated reasonably well with the look of the TOS films, which made sense for a cutting-edge ship. And that was also well underscored by the way the Shenzou looked more Enterprise inspired, right down to using the NX-01 style lateral transporters versus Discovery’s vertically aligned ones.

That’s to say, Discovery used Trek design elements from different eras intelligently, to communicate the different roles and histories of these ships. Very much the opposite of throwing it all away.