It's a difficult, but interesting question.
If a Shenmue III with the exact same dialogue and plot and systems, but only downgraded graphics and the VF fighting engine, had come for the original Xbox in 2004, I guess it would have been panned way harder than the real 2019 game. Having the grand Shenmue II experience so recent, and the expectation of the Shenmue franchise being industry-leading, would have made that game a real shock.
However, the more realistic possibility of a 2004 Shenmue III with the main story beats we got on the 2019 one, but a bigger budget and Sega's talent to polish the writing, dialogue, cutscenes, music, QTEs, etc. would have been really well received among fans of previous games. Although I also think it wouldn't have expanded the audience significantly.
If a Shenmue III with the exact same dialogue and plot and systems, but only downgraded graphics and the VF fighting engine, had come for the original Xbox in 2004, I guess it would have been panned way harder than the real 2019 game. Having the grand Shenmue II experience so recent, and the expectation of the Shenmue franchise being industry-leading, would have made that game a real shock.
However, the more realistic possibility of a 2004 Shenmue III with the main story beats we got on the 2019 one, but a bigger budget and Sega's talent to polish the writing, dialogue, cutscenes, music, QTEs, etc. would have been really well received among fans of previous games. Although I also think it wouldn't have expanded the audience significantly.