> Define significant part. There are people in 2020 living in absolutely abhorrent slums. Most major US cities have areas meeting this definition.
The 1920 slums meant living at 5-10 people per room, with no running water, in constant stench from the nearby factories. I doubt you can find many places like that in US today.
> Unsure if this is true.
That's what the data I've found says - average time worked in non-agriculture was close 3000 hours per year (so, 60 hours per week for 52 weeks per years - no sick days, no vacation). Plus constant risk of death or maiming, plus obviously inhaling all the deadly pollution etc. (Communist countries at least started recognizing that conditions of working in a coal mine or steel mill will literally kill you over time, and gave those workers full retirement after "just" 15-20 years of work there). Conditions were bad enough that people were risking their lives trying to start trade unions. Many were killed for it, too. How many trade union members were killed in 2022 in the US?
Women didn't worked at jobs, but slaved away at homes. Living without modern amenities plus large families meant a mountain of work. For example, my grandmother didn't have a washing machine and washed the bed linen by hand, which meant 10+ hours of physical labor. She insisted on doing that every 3 weeks or so.
> Suicide rate in the US has been steadily climbing decade over decade. What does that say about our living conditions?
Hard to say? For example, during wartime (cannot imagine harsher living conditions than war), number of suicides can go down significantly - they did in the UK during WWII for example. The relation between living conditions and suicides are complex at best.