Yeah, Betts was on Arb when they won. He signed the next year and I think it was before he even hit free agency.
Alex Rodriguez won a WS on a 10 plus year deal so I know it has happened. I will add though that most of the 10 year deals that were better were all during the heavy PED Era. Now that the league is more closely monitored I think we will see players generally start to decline sooner and more steeply.
I really hope the Cubs avoid these types of deals. Most hitters will be in full decline past 34 so half of these deals may be bad years where you are paying someone and filling a bench spot that is functionally worthless.
MLB will have to adjust to post heavy PED Era. These deals should be about 8 years.
Lastly, I say heavy PED because while I am sure players are still cheating I don't think it is as prevalent or players are gaining as much benefit.