There have been brief periods where civility was normal, but politics and extreme heated emotion and polarization are the norm. Murder, mayhem, riots, extreme, ridiculous mud-slinging, and simmering turmoil have been the default state for a majority of human history.
Social media has exacerbated things in some ways, but in others, it's imposed an artificial civility as people get settled into their bubbles and vent online instead of taking action.
Just look at all the political violence in each decade of the 20th century in the US. Look at all the bombings, arson, murder, riots since 1950.
The dynamics have changed, but it'll be decades or more before humanity is anywhere near culturally settled down with the internet and instant global communication. It's already a net good, but massive online platforms and entrenched power players manipulating narratives and so on still need to be calibrated in policy.
The civility you remember might simply have been that all the violence wasn't being reported and headlining in major outlets 24/7. The threshold for newsworthy events and the willing participation of news outlets in managing perception created a very sterile and civil seeming facade over what's been more or less constant chaos.