If by design elements you include vector images, you could try https://www.recraft.ai/ or Adobe Firefly 2 - there's not a lot of vector work right now, so your choices are either the handful of vector generators, or just bite the bullet and use eg DALL-E 3 to generate raster images you convert to SVG/recreate by hand.

(The second is what we did for https://gwern.net/dropcap because the PNG->SVG filesizes & quality were just barely acceptable for our web pages.)