Maybe they are not better....maybe they just look better....maybe it’s they’re cheaper to build compared to a riveted boat....why are aircraft riveted and not welded...are riveted boats less costly to repair....welded small boats are usually lighter ...what about reinforcing braces and brackets...what about using heavier gage aluminum ..riveted boats allow the boat to flex and not break...welded boats are stiffer and not as flexible ..does a small performance tinny even need to worry able flexibility?
There are many opinions on the websites especially from the boat manufacturers . I remember when the first small welded tinny China built boats appeared on the market. The sales promotion was they were lighter, stronger, better build and less expensive compared to the current ageless riveted North America built hulls that had been the same basic designs for years.
If you check the marketplace today those China boats have increased significantly in price and there appears to be a surplus of new old stock models.
Here is a video about difference welded and riveted .
https://www.youtube.com/watch?v=6ZE_axfUN3cBuying a new small tinny with a small 4 stroke outboard is now a very expensive purchase. That reason could be the reason for the reduction in sales.