But was it? The population has increased quite a bit so it depends what you mean by 'commonplace' - gross numbers, or 'poor per capita'?
The opportunity may exist to rise above it, as you say, but the biggest root cause for there being poor people is that only a few can hold onto the majority of funds in an economy, and they'll generally be in a good enough social position to protect that.
Money heads upwards. The specific pressures haven't really changed significantly (well, the form has slightly due to changes in culture and technology) but if anything the barriers against people trying to get out of poverty have multiplied. Even a lot of people on benefits have a TV in every room, telling them which consumer products mean more to them than a good diet. Even a mere century ago, there wasn't very much the average poor family spent money on that wasn't food, clothing, shelter or necessities like doctors' services.