Well yes, Russia is Russia. The RBMK with its well-known design flaws could never have been certified/built in the West. Yes, these design flaws were well-known long before the Chernobyl accident.

In his posthumously published memoirs, Valery Legasov, the First Deputy Director of the Kurchatov Institute of Atomic Energy, revealed that the institute's scientists had long known that the RBMK had significant design flaws. Legasov's suicide in 1988, following frustrated attempts to promote nuclear and industrial safety reform, caused shockwaves throughout the scientific community.

https://en.wikipedia.org/wiki/RBMK#Improvements_since_the_Ch...

A list:

https://en.wikipedia.org/wiki/RBMK#Design_flaws_and_safety_i...

However, the units that are still operating were modified after the accident to remove at least a few of the elements of the accident chain that made the reactor inherently unsafe.

Still no containment, and still not anywhere close to the requirements for Western reactors, but they seem to be operating reasonably safely.

There’s still 7 RMBK reactors running, I believe.

And other than Chernobyl no melt downs.

So they seem to be fairly reliable if they aren’t run by clowns.