Not one of them has ever explained where he could have come up with ~$200 billion (or the old numbers, which were more like $40b to $50b) from. There is no entity inside of Russia capable of spitting off that kind of hidden side profit - just for him - in the time frame in question. Their entire economy is a mere $1.5 trillion. If you figure most of the graft occured in the last 13 to 15 years, where was he siphoning $12+ billion per year from? Again, there are no entities in Russia capable of subtly delivering that sort of cash.
If he owned 100% of Rosneft (or Lukoil) and Gazprom, he'd still be worth closer to ~$100b-$120b than $200b. Needless to say, he doesn't own those two. He'd have had to be taking a very large share of the annual total industrial profit of Russia, to squirrel away these sorts of numbers over time.
The notion that Putin is secretly the richest person (they keep increasing the mythical sum over time to stay ahead of Gates etc), is nothing more than empty bravado that Russia likes to encourage to artificially prop up the projection of power that Putin relies upon to govern.
That math almost certainly extends to most of the economy because this kind of corruption is damn-near omnipresent in Russian society. I'd need both hands to count the number of times my travel plans were disrupted because someone stole the funds for antifreeze (in Sheremetyevo International no less) or airport/train/border security. Likewise, you could see at Sochi just how vast the chasm was between what was budgeted for and what was actually built. The sheer scale of it is more than enough to generate a few hundred billion dollars for a single person, after paying off all the levels below to maintain power.
Also, what evidence do we have that the stolen funds are even included in the GDP calculation? Are the indicators used to estimate GDP susceptible to the same corruption or can they effectively?
He might not be on the corporate hierarchy, but his decisions override the board.
I would expect that he diversified his wealth all over the world via 'friends', stored in shady wealth management companies, well located banks, and probably few tonnes of good old $$ and gold. Some bankers in one Zurich bank might give you some info (but might not be alive to confirm it afterwards).
But he has good PR - it often looks ridiculous to western eyes, but for most russians it hits some obscure sweet spot. And of course he is not some lone wolf, rather guy on top of a massive pyramid with tons of FSB people who know their stuff a bit too well.
Who else would you be expecting to run huge broken country like Russia for so long so successfully? I mean, even Arafat died as a billionaire, and Palestine ain't some Eldorado to begin with.
That said, it's sort of beside the point. Unlike petty dictators, Putin holds real and substantial power--power that money can't buy outright, and power that he'll probably continue holding until his death. He doesn't need an exit strategy and a golden parachute. OTOH, he secured much of that power redirecting assets. It's less unbelievable that Putin has deliberately permitted $200 billion of embezzled funds to be redirected to those who do his bidding.
He doesn't need the exit strategy now, but it would be stupid of him not to have one (probably more than one), because nobody knows what future will bring. You only need one charismatic opponent to undermine him.
Overall I think he isn't a bad person for the position he has - he is definitely not outright evil, also definitely not weak and probably quite a patriot. But Russia could have achieved much more than where they are right now, with better leadership. At least in theory.