ELI5:why does nuclear fusion bypass beryllium an go straight to carbon

A question from my 9 year old. In nuclear fusion (in stars) first helium (atomic number 2) is formed from hydrogen (atomic number 1) by combining two hydrogen nuclei. When all the hydrogen is gone, instead of two heliums combining to form beryllium (atomic number 4) which seems the easiest and logical next step, three helium nuclei combine to form carbon (atomic number 6). Why wait to combine three helium atoms when it seems easier to combine two.