Ion engines don't help you at all in interstellar distances. Not even for moving people around the solar system as they take forever to gain speed. They are nice to send unmanned probes to far away places in the solar system in multi-year missions and that's about it.

I'm not disparaging ion engines tech, it's wonderful. But falls terribly short of the sci Fi stuff the OP mentioned.

The sad reality is the only likely development left with the physics we know is nuclear engines, and those would still allow for slow but bearable transportation inside the solar system.

Nothing we have or can build with our current tech and understanding of physics allows interstellar travel, at all. Never mind quick and easy interstellar travel like in sci Fi.

If you mean traveling inside the solar system, yes, that seems a likely estimate.

If you mean interstellar travel, either we find a loophole in physics that allows for traveling at a significant portion of C with our current energy sources, it we find a new energy source,, or the answer is never.

Science fiction has caught up and surpassed reality where physics allow.

Our mobile phones are way more advanced than any intercom system in old sci Fi shows. While at the same time our spaceships work pretty much in the same way than in the 60s

Physics allowed for one thing and made the other extremely challenging. The solar system is the ceiling with the physics we know, and barring new physics, it'll remain that way forever.

Thit.

Between 20 years and never ever, depending on whether it's possible at all, and then, even if possible, on wether it's actually feasible for tiny, delicate, short lived and insignificant human beings.

Any challenge in transportation we've mastered till now is nothing in comparison with the challenge posed by interstellar travel. And that was knowing physics allowed it.