Ah, the classic "Ship of Tramiel" gedankenexperiment.

There is a belief among Amiga enthusiasts that the Amiga should have won, that had it not been for sabotage from without (e.g., Microsoft) as well as sabotage from within (upper management, particularly Irving Gould, being interested in squeezing profits out of the C64 and existing Amiga lines rather than R&D), the Amiga would have been a decade or more ahead of the rest of the industry and may have become the dominant computing platform. Kitting out Amigas with more advanced hardware than any real Amiga would have been able to be contemporaneously equipped with thus becomes an alternate reality game: what if Commodore hadn't failed? what if the Amiga were still a contender into the late 90s and beyond? To borrow your analogy, it's like kitting out a 1967 Chevy Impala with a modern engine and drivetrain, to imagine what it would have been like had the values of the '67 Impala, including looks and the sense of being fun to drive, had persisted into the era of fuel injection and continuously-variable transmissions. Maybe it's not an Amiga in terms of actual Amiga hardware configurations, but the idea is that in this alternate universe, what an Amiga is would have changed.