Can anyone explain why trail running is getting so popular?

Trail running is the 7th fastest growing sport in the United States and the fastest growing running segment but I haven't seen any clear indicators why.

A few theories:

• Ultramarathons are becoming more popular with the visibility of UTMB, Leadville, etc. Brands and media are covering these races more every year because people are breaking records. So, more trail-curious runners head to trail races even if they're not at the ultra distances.
• Trail is, in some ways, safer as it encourages slower running despite being more technical. We may just see older runners who aren't running for PRs any more turn to trail.
• Brands were looking for new verticals and so invested into athletes and content in this space (lots of content from HOKA, Wahoo and beyond) to expand their total addressable market.
• Some other reason!

I'd love some theories.