Why is silicon oxide giant covalent structure?

Why is silicon oxide giant covalent structure? Why it doesn't bond like carbon dioxide?

Elements of 3+ rows are not happy with double bonds, they prefer single bonds unless you delve into hypervalent compounds like $H_2SO_4$ where 'double bonds' are actually dative singular bonds.
For this reason, $SiO_2$ forms structure with only singular Si-O bonds. It happens so that for it the only way to form one is to make 3-d infinite structure.
For similar reason $N_2O_5$ is exactly like this in gase phase while $P_2O_5$ forms tetrahedric $P_4O_{10}$ and $SO_3$ loves to form trimers and chains.