Even with the lightning network going full mainstream with major companies accepting Bitcoin as a method of payment worldwide, I don't think we'll see 500k, not in 3 years and not in a very long time.
Do you believe McAfee is right about Bitcoin hitting $50000 in 3 years?
The guy is a clown, but 50k in 3 years doesn't sound too bad imo, considering that we might see another bull run in the next few years, plus a massive wave of bitcoin adoption, I'd say the probability of reaching the 50k mark is very high.