People usually search for the best children's book publishing companies when they are somewhere between excited and slightly overwhelmed. Which is fair, because there are a lot of options and they do not all feel the same.
Some publishing companies for children's books are very system-heavy. Very formal. Very “submit and wait.” Others are more collaborative. The better children's book publishers usually sit in that second category, where someone actually reads your work and responds like a human, not a checklist.
And honestly, children's book publishing companies differ a lot in how they handle illustrations and pacing. That is where things either click or fall apart. Publishing a children's book is not just printing pages; it is timing, visual rhythm, and whether a child actually wants to turn the page or not.
You will also see a lot of kidsbooks publishing tools and platforms trying to make everything faster. Sometimes that helps, sometimes it flattens the story a bit. Depends on how it is used.