Side note: If cost is an issue, converting a hardtail to monstercross/gravel spec is very much a thing. And quite often results in bikes that are better descenders and better at washboard, potholes, ruts and sandy surface than all-road bikes twice their price.
That's what I've done with my 1997 Marin Indian Fire Trail: 26" hardtail frame with old-school geometry, so while it's a bit of a handful for modern-day XC riding it's the bee's knees for gravel and monstercross. I swapped out the flat (and narrow by today's standards) bars and long stem for a shorter stem and some Salsa Cowball bars, repurposed some 10-speed Campagnolo Chorus brifters (which can shift 8-speed Shimano drivetrains without any converter cams), and put on less aggressive tires.
I typically don't run the SKS ShockBlade unless it's a muddy ride. The old Answer Manitou fork has a new aftermarket elastomer kit so it works similarly to a Lauf fork. The pedals seen here (the SPD one side, flat cage the other) have been replaced with Shimano XT Trail SPDs.
This bike simply
rocks. It's super comfy on gravel and pavement, can handle singletrack with ease, and is really dialed in for long distance riding. The one thing to keep in mind if doing a hardtail-to-gravel conversion is cockpit setup. It's really easy to get wrong given the differences in riding position between flat bars and drops. It works more easily on old-school geometry bikes than new-school with slack angles, to be honest - a good reason to trawl Craigslist, eBay, or a local bike co-op for an old-school hardtail frame.
I rode a 104 mile mixed-surface ride on this bike last weekend and it basically disappeared under me: total comfort and felt totally fresh at the end, even with some technical gravel segments mid-ride (the route ended up being about a 60-40 split of gravel to paved). I've raced it on some more gnarly gravel routes (e.g. ones with rock gardens and embedded babyheads, as well as washout and creek crossings) and it just plain works.
This conversion gave this bike - which had previously been relegated to commuter use only - a whole new life.