I think there was actually more understanding of human distress and pressures in the past
People knew of babies and children who died young, mothers who died giving birth, neighbours, friends who died of disease and men who died in war and having to flee invading armies. That's on top of the everyday distress like losing your job and having to resort to the workhouse, being thrown out by your landlord or finding out your husband has gambled and drunk away the housekeeping and you're all going to go hungry. They couldn't avoid suffering by way of trigger warnings, they were in the thick of it and they had to deal with is as God's will or however they saw it.
We live in a society in the west that's largely sanitised and safe, certainly the most sanitised and safe it has ever been. Doctors can cure conditions that fifty years ago would have been a death sentence. Cars are the safest they've ever been and health and safety warnings proliferate. We can take for granted clean water, heat and light and sewage so diseases our great grandparents would have encountered are practically unheard of. Trigger warnings almost feel like they're putting that danger back into life - 'warning! you're reading a Thomas Hardy novel that might arouse uncomfortable feelings and make you sad!' 'Careful, you might see blood on these biology slides!' 'Beware! this book was written in 1923 and has the attitudes of the time!' It's like a mass infantilisation.
(Disclaimer - I do realise that some people have suffered genuine trauma and trigger warnings work for them).