why is DNA a better genetic material than RNA?

DNA is a better genetic material than RNA as:

1. The 2-OH group present at every nucleotide in RNA is reactive and makes RNA labile and degradable. But, DNA is less reactive and structurally more stable.

2. The presence of Thymine in place of Uracil in DNA confers it additional stability. One major problem with using uracil as a base is that cytosine undergoes deamination and gets converted into uracil. This is not a rare reaction; it happens around 100 times per cell, per day. This is no major problem when using thymine (as in the case of DNA), as the cell can easily recognize that the uracil doesn't belong there and can repair it by substituting it by a cytosine again.