CD4050B: CD4050B Input dt/dv limitations ?

Hello

I was studying the Data Sheet for the Max dt/dv on the Inputs while thinking of using this

for RCD Timing control for up to 4.5 uS, using 15 V Logic, for large IGBT Drives

Can someone please explain Fig 9.2.3 of the Data Sheet :

" igure 9-3. Typical Power Dissipation vs Input Rise
and Fall Times Per Buffer for CD4050   "

Best

Varun