Maybe, I don't think it was announced for a while but I'm sure you're right and they were approaching Spielberg and he wasn't saying yes. Maybe if he'd just given a definite no at that point then we might have got it sooner, maybe more than one.
(And I don't blame him for not wanting to do it- I'm not sure he really wanted to do any more after Raiders!)
I think Spielberg has had zero artistic drive the last 15 years. He can greenlight any project he wants and the last ten years, he's made "Bridge of Spies", "The BFG" (IMO, his worst film), "The Post", "Ready Player One" (which he was perfect for, but the film was underwhelming), "West Side Story", and now on the upswing with "The Fabelmans". Hints of greatness here and there, but nothing truly groundbreaking or awe-inspiring. At the same time developing other films and passing on them ("Memoirs of a Geisha", "Interstellar"). Whereas Scorsese is even older and is as inspired as ever to make interesting films.
And before Spielberg was being wishy-washy, it was Lucas spending nearly 20 years refining the aliens idea for KOTCS. In an even more ideal world... Lucas handed over directing duties for Episode II and III like he did for Episodes V and VI. We got better films there... and he could give more of his attention fo the Indy franchise. We get an Indy 4 anywhere from 2000-2004, and potentially a fifth Indy film from Spielberg 2007-2013, before his malaise set in.
To quote Harold Oxley, "How much of human life is lost in waiting..."