The Sarmat missile is Russia's largest ICBM, with a height of 115 feet (35 meters). It is capable of delivering nuclear warheads to targets more than 11,000 miles (18,000 kilometers) away, making it the longest-range missile in the world.
On paper, it's impressive. In person, it's embarrassing.
It would be impressive were it properly maintained using the funds allocated only for the stated goal.
But I'd expect that to not be the case.
And also when a significant part of the chain is interested only in stealing, there will be negative selection. Everybody capable of learning will leave for greener pastures. Those who remain will be dull and full of themselves.
To put that into perspective, the circumference of the earth is ~24,000 miles. From my rough Google Earth calculations, the stated range covers the entire planet except for a tiny sliver of Antarctica and a bit of the ocean nearby.
Why would Russia need a missile with that range? Unless they just really want to take out New Zealand first, it kinda seems like they just picked the largest sensible range value (12,000 miles, halfway around the planet) and then fudged it down a bit because why would you need to fire a missile more than halfway around the planet? Just fire it in the opposite direction.