It's a tidy build, and I guess it's a fun kid's toy. Wood is a baffling choice of material for a (lawn) tractor chassis by someone who clearly owns a welder. Don't start lecturing me about Morgans and ash-- that's a whole different thing, and there's a reason they're basically the only serious company still shipping a wooden vehicle chassis.
I'm a farmer, I know what working vehicles are subjected to over time, and I know that when plywood gets wet, it swells, warps differentially, splits at its layer boundaries, and starts to twist. Tractors are for driving over land that is often at least damp. This is not a recipe for durability.