Do you think he will be able to return the money? Most of those scammers dont have other sources of income, they depend on the crazy activity which they do for survival, and after scamming someone, they always end up lavishing the money, thats when you going to see them going to clubs, buying expensive cars, leaving luxury lifestyle. If people like this are caught, they wont be able to refund the money, because they will have started spending the money already.
All what I feel they can do is just to sentence people like this, but I think 20 years is kind of small, they should have increased the years which they going to spend in prison, when others see news like this, its going to discourage them from involving themselves in activities like this.
Sentences is what will fit this scammer if such age, they have nothing tangible to do with the money, and from the news, the scammer has spent almost all the money, they dont have other plans than to party and to spend the money unnecessarily, there is no way they can find even 50% of the money he took from the wallet,
I will have to blame the owner of the Bitcoin for letting such thing to happen, large about if Bitcoin should be more secured than just using google drive to backup seed phrase, I believe with that big amount, the owner should engrave his seed in a metal and keep it in a safe place for more protection because these digital devices can get compromised.