Except that kids tend to destroy things (the binoculars obviously, not a trowel), tend to be violent with and throw things (a real gardening trowel is heavy and could injure their sibling for life), and quickly lose interest in things (they forget about the $20 binoculars long before their lack of quality is apparent).

I mean it depends on the ages of your kids... but there are very good reasons most toys are cheap plastic. It didn't just happen accidentally. It's a feature, not a bug. (Except for landfills, of course.)