I have a personal spin on this well worn topic.
I love the gravel bike I bought for my son and need to stop stealing it.
The plan was to get myself a dedicated Gravel bike (I have a road bike) but the more I ride the gravel bike the more I realize that I love the gravel trails....but I want to go further offroad.
I tried taking the gravel bike into the more difficult stuff but was soon overmatched by giant holes, sharp pieces of tree stumps and even steel, lots of metal. Even if I were younger the gravel bike would get eaten alive it was so rough.
Really, this was something best suited for a full squish, but I don't like suspension.
I really like gravel bikes because they are fast, I can power along at 15 plus mph on dirt/gravel whereas I could not keep that pace on a dedicated MTB.
I was thinking that a carbon fiber hard tail 29er might be the best compromise, but I would love to hear the opinions of others.