Scientific American has an interesting interview with an author of a study showing a decline in sexual activity among young and middle aged, single and partnered, whether alone or with someone else. (I didn't see that the study or studies involved in this conversation talked about people over 50.)
Source:
https://www.scientificamerican.com/article/people-have-been-having-less-sex-whether-theyre-teenagers-or-40-somethings/
A recent study evaluating what is happening in the U.S. has added to the pile of evidence, showing declines from 2009 to 2018 in all forms of partnered sexual activity .... Between 2009 and 2018, the proportion of adolescents reporting no sexual activity, either alone or with partners, rose from 28.8 percent to 44.2 percent among young men and from 49.5 percent in 2009 to 74 percent among young women. The researchers obtained the self-reported information from the National Survey of Sexual Health and Behavior and used responses from 4,155 people in 2009 and 4,547 people in 2018. These respondents to the confidential survey ranged in age from 14 to 49 years.
The author figured there were several potential explanations and that just one factor probably wasn't "the reason." But potential factors discussed in the article include social media, video games, increasing acceptability of asexuality, fearfulness about 'rough sex,' socioeconomic declines, and declines in the use of alcohol. The study did not include data since the onset of the pandemic, but the author is asked to speculate on the impact. (She figures it's a mix. More time together at home, but also more time together at home. lol.)