I think there is an opportunity for Strava to promote long and hard "FKT style" segments - those that require a race like effort and take at least an hour to complete, preferably several hours. Those would be great free alternatives to virtual races. These "FKT style" segments should have detailed descriptions on Strava with photos, and perhaps even comments.
Ideally these segments must represent some real FKTs (https://fastestknowntime.com/), and some integration with FKT website could be a good first step, however Strava selection of these segments could be different. These challenges would draw multiple attempts from various people and might also be a way to promote subscription only features. For example, having support for Live Segments on a Garmin, Coros, Polar, or Suunto watch would be super beneficial during those long FKT attempts. Perhaps, Strava could position these segments as virtual races and require subscription to access these. But in exchange there should be some quality content and perhaps even badges for completing these segments.
With the current popularity based implementation of segments, these long segments are very hard to impossible to discover. The only way I usually find those segments is by looking at some else's activity. Then I make sure to star the segment so that I could try running it in the future.