Because they have more catenation.
There are four reasons why carbon can form strong bonds with most other elements:-1) Tetravalency :- Carbon has 4 valence electrons in its valence shell therefore it can easily form covalent bonds.2) Isomerism:- Carbon can form compounds which have the same molecular structure but different structural formula.3) Small size:- Carbon has a small atomic radii therefore the nucleus can hold the shared pairs of electrons firmly.4) Catenation:- carbon has a unique ability where it can form strong covalent bonds between atoms of itself.