I’m not sure who decided that “spot clean only” is acceptable for children’s items.
When my oldest were small, mattresses had nice thick, smooth covers that could be cleaned quickly and well. Today, crib mattress surfaces are soft fabric. Apologies for being graphic, but if you don’t want to smell infant/toddler sickness for years to come, this requires you cover it with a waterproof mattress cover. No amount of “spot cleaning” will erase that smell/stain/evidence from the mattress otherwise.
Now, I know people have been concerned about the chemicals in the vinyl/plastic covers that were on most crib mattresses. But, small children also make significantly larger messes in their beds than adults so a different solution from adult mattresses is warranted.
I have a similar issue with stuffed animals. Again, they are at risk if you have a sick child (who inevitably piles all their friends in their bed). Why can they not go in the laundry? Some have bells or squeaks, but for others I suspect the manufacturers just don’t want to be liable if it comes apart in the wash. I have washed many stuffed animals over the years and most have come out just fine. What else do you do with your child’s best friend?
Finally, never should an infant or toddler outfit be dry clean only. There is no need. There are so many nice fancy outfits that can be machine washed. Only an heirloom should go to the dry cleaner.