Check out the videos and photos for the November 2018 ruta de los conquistadores. Looks like all hardtail, no-suspension 29ers.
Lance Armstrong was among the participants, just there to ride and finish, nowhere near the top. Looked like a tough ride, but the 29ers seemed appropriate for the terrain.
There are some good comparison videos on GCNs mountain biking channel.
I'm not really into mountain biking but have my eye on a 1990s Kona Lava Dome for gravel and moderate tails rides. At 61 I'm too old to learn new tricks.