This is definitely true. There is now much less “clear blue water” in terms of quality between a Frog and the better of the more mainstream offerings.and in the meantime the big bike brands and e.g. Halford have raised their game with lighter bikes with child sized brake levers etc.
There are, of course, still some truly horrible kids bikes on the market at the very cheapest end of the spectrum, just as there are still some truly horrible adults bikes on the market.