You mean slaves versus serfs? One could actually argue either way. Slaves got whipped, but they had guaranteed home (not saying that that makes it acceptable in any way, etc). The fact that the ex-slaves were tied to their land and had fortunes riding on the season made them more free, which is both good and bad.
Assuming you mean to refer to WASP working conditions, the bottom rung is the bottom rung. In the 1660s, they would mostly be people working for farmers (because you are obviously talking about people who don’t actually own the land). In the 1830s, they would, once again, be agricultural workers, with some urban workers.
If you want to talk 1880s, it gets more urbanized, until your poor are mostly migrant and shop workers.
Fact is, people who always just got by always just got by, under any economic system.
Did things get better? Well, yes, technology got better, so the standard of life for almost everyone rose. Your best argument would be that capitalism fired the kilns of science, and inspired more rapid development of new ideas. Part of that is the problem - as there are more things to buy, the cost of the standard of living goes up. In the 1660s, you only had to own very little to “just get by.” By the 1880s, it was a different story, and by the time you get into the 1900s, you have all kinds of electronics appearing that made “just getting by” much more expensive - and really, that is the truth. The lowest rung is defined as the lowest rung - there is no set level of income to define it. It could be pointed out that “just getting by” in many places in America these days (say, Los Angeles) can include cable television, 2 cars, a family computer with dialup access, and a smallish Christmas. In terms relative to the world and history, that is fairly luxerious, considering that 50 years ago people still had ice boxes and most didn’t have TVs.