Linking Identity Document in UKVI Account

Hi,

I am on Indefinite Leave to Remain. My UKVI account was created last year with the Biometric Residence Permit as the identity Document. I recently renewed my Indian passport and I was wondering if I need to link it to my UKVI account. I didn't link my old passport with UKVI account and didn't have any trouble in passing through immigration so I was wondering if it's actually required?

Thanks