Option A) Build a lot of sets, recreate a lot of cars, hire a lot of extras. Pay a lot of money.
Option B) Use fancy computer graphics to dress the set, put your money where it needs to go and let the rest of it be done through special effects.
George went with Option B. Nobody really noticed. And that was the point. This farce was made on the cheap because of (now) 10 year old technology... actually, even older, probably - nothing was all that cutting edge, but Lucas was interviewed as the movie was opening up and he said that this was the real promise of all that fancy stuff that he's so connected to.
Cut to: a picture of a calendar with the months tearing off one at a time, quicker until you see the years passing by, and we land on:
George Lucas is now off in his own little world. Mostly his fans think he's lost his mind. Presumably he's pressing on, tilting at crazy Star Wars windmills. Things like trying to get a Mountain Dew product placement in the middle of a lightsaber battle.
And a film comes along that does Lucas a little bit better - it, too, recreates The City. Not quite as cheaply as Lucas had envisioned, but they were going for something a little different.
Seems to me they did a pretty reasonable job at capturing the Buck Rogers grainy film serial look and feel. And the dialog - is it an homage, or is it just bad? I leave that to you to decide.