Turnovers were happening at the lowest frequency in history in 2020. There were only 665 in the regular season and that came out to one every 49.5 plays. That was the best rate in league history (from the perspective of the offense) or the worst in league history (from the defensive perspective). The highest rate happened in 1971 - one turnover every 23.1 plays.
This graph shows that taking care of the ball has gotten much better throughout the history of the NFL since the merger. This century the trend is accelerating.