I'd say, without evidence, that parenting has improved dramatically over time. Despite all the issues with parenting today, I really do believe it used to be significantly worse going back further and further into the past.
The main difference is awareness. People see more now how what they do affects their children in the long term. Abuse can be made immediately visible, and is often illegal. Positive reinforcement has taken a step forward in place of negative reinforcement and especially corporal punishment.
And yet we still are in a position where more can be done.
One of the biggest things we've lost over time is unfortunately the ability for parents to spend time with their families. Both parents work all day. They don't have time for their kids. Some parents work multiple jobs. This is a symptom of the worsening wealth inequality, and really an economic issue more than anything.
There are still bad parents, of course. I knew a couple growing up. It's just more visible now due to increased awareness.
