In most cases i would agree but Soto's age kinda changes the game here, or so to speak.
Most free agents usually that benchmark in their late 20s/early 30s which factors into negotiations somewhat since you usually only see 10 years as the upper limit on term.
Soto being so young, relatively speaking is more than enough to throw on more years which is why you're seeing the money climb up into the 6, or perhaps even 700s. He won't be making more than Shohei annually but he will still get close to his total number just on this alone imo.
If he was this good at age 30, he probably gets a much more familiar 10/500 rather than 14/700 as we've seen rumored.