I'm thinking because they can chamber revolver cartridges and be an optional firearm when carrying the same caliber in your pistol. Duo punch with one cartridge.
[snip]
That's what i think, too.
With ammo prices what they have been, and (lack of) availability, it made more sense to reduce the number of calibers needed for your firearms.
Having a carbine that shoots ,22LR, 357 Magnum or .44 Magnum makes it easier and more affordable to find and buy the caliber you needed for both a long gun and pistol/s. Compare that to the prices and scarcity of most rifle ammo the past few years. No need to double up or triple up on your hoarding to acquire multiple calibers.
The smaller size rounds are also easier to stockpile in terms of weight and space needed for storage.
So, to me, it would be mostly an economic decision.
Another reason is that cycling a lever action is faster than a bolt action rifle. That makes it more suitable for home defense than a bolt action. Not as much fire power as a semi-auto AR, but it's still a good option -- similar to a pump shotgun in speed of cycling the action.
Those are the practical reasons, but i think nostalgia also factors in. Few cowboy movies don't have a lever action rifle involved. It's a part of American history, and a design that's still relevant for many purposes.