Could the Moon be inhabited by people in 50-100 years?
Yes and no.
There are no clear estimates for the speed of non-Earth colonisation, but if Scientific Progress continues accelerating at the same rate, we would be close to colonising the Moon within 100 years.
A few thoughts...
There are various obstacles that make inhabiting the moon unattractive...
The moon's gravity is insufficient to retain a significant atmosphere. So the population would have to inhabit artificial structures.
The much lower gravity could cause health issues for long term residents.
The moon lacks a magnetosphere. So there is no protection from cosmic rays. So long term stays are likely to be injurous to health.
The moon seems to lack essential resources which would have to be transported and carefully recycled: oxygen, water, etc.
What would be the advantages of being on the moon?
- The very sparse atmosphere allows much clearer views of space than we get from the Earth's surface.
I think that's about it.
With advances in robotics and AI, why would we bother to have actual people on the moon suffering the harmful environment?
All this having been said, I can imagine having a habitable station on the moon's surface that might be staffed by research scientists in a similar way to Antarctica today.