Why are the hard-tipped copybooks written in Tian character grid and not in rice character grid?

It is indeed a copybook with rice characters

See the picture:

One search on the Internet will lead to a lot of recommendations

But now it is generally started When learning to write, use Tian Zi Ge, because Tian Zi Ge also has the function of practicing calligraphy

But Mi Zi Ge is more accurate than Tian Zi Ge

It’s just that Tian Zi Ge is more accurate to use. for extensive