Retirement is virtually impossible for people who live in poverty because when one is poor, literally every dollar and penny counts. It's sad but that is the truth. They need to be able to live now and because they're living now, their futures are insecure because they are not able to save for retirement.
The key to retirement is saving. Many people start to late or don't know how to prepare for retirement. It's important to provide everyone with the information needed to prepare for retirement. It should be a priority to help people understand their options and how even saving just a little bit now will help them meet their goals. Saving for retirement isn't easy, but it's possible if you start early and know what needs to be done.
No, retirement in the low to middle-income families is not going to become impossible, but it will likely look very different. Older people may have to find ways to have partial retirement where they work part-time or possibly take over child care or cooking and housekeeping duties for younger family members.
No, I don't think that retirement is a thing of the past. Physically, people are not able to work until the end of their lives, so retirement will almost always occur. I do think that people need to start planning ahead for this though instead of just expecting the government to take care of them at the end of their lives.