Any Londoners here or people familiar with London ?

I think all London accents are dying out. The majority of the city wasn't born in the country.

I think the Brooklyn accent is dying as well.

Central London is pretty multicultural, you don't hear many British / English accents never mind Cockney, which is only spoken by a small minority today. MLE is probably becoming the prevalent accent amongst younger Londoners, in which you'll hear things like "innit" "ting" "d'ya get me bruv". I found this excellent explanation on metafilter.com;

"A new London accent strikingly different from Cockney has emerged in the last few years. Linguists call it "Multicultural London English" (or MLE) and although it has obvious roots in the London black community it's now displacing Cockney to become a universal accent for working class London youth, regardless of race. Change is spreading so fast that London teens often have radically different accents from their own parents."

The cockney accent has survived, most notably by Americans trying to do the Australian accent and failing. 😂

To me she has a hybrid accent, I wouldn´t call her accent pure cockney. I can hear some Australianisms too. If its cockney its mild, I´d consider someone like Naveen Andrews or Adewale Akinnuoye-Agbaje as having a proper Cockney accent.
https://www.youtube.com/watch?v=XIL-6L25aZE