If arrests were the only barametor used to determine viability than the Colombo and Gambino' s would be considered possibly defunct.

We haven't seen a big pinch in either family in about 7 years..
And the same with the decav and we can keep.going...

The real reason is the amount of resources expended on LCN.

Back in the 1980's when Regan took office he authorized the hire of 1000 additional FIB agents to target LCN,

Now there are less than 50
You see the difference?

The feds spent 100,000,000 MILLION just to get Gotti.

The other thing is by design.

LCN was always supposes be a secret society

There never should have been social clubs where all known member should associate and do illegal business.

The plan is to make them think they no longer exist so they don't come after them as hard.
..
As a whole crews are more independent these days again by design.

So if someone flips the exoposure is limited to that one crew not the whole.heirchary or other crews.

No more social clubs, so it's harder to be identified.
No more murders brings too much heat.

Shouldn't be having X-man parties as you see from the Bonnano's and Merlino they Jammed up at the parties.

Besides that most have pretty solid legit businesses so they are snot taking the risks like they used to.

So you see collectively you are not seeing the amount of arrests, indictments, guys flipping etc...