I found a cigar shop in Spain with a walk in humidor and somewhat overspent, considering I don't really smoke - except the very occasional cigar. I now have 20 coronas and maybe 40 cigarellos. That's about 4 years worth of cigars for me.
Are cigars even good for that long?
Yes and at least ten to twenty times that long, if kept in proper conditions.
I'm more of a pipe smoker than a cigar aficionado, but the processes are very similar.
The Danish tobacco I smoke is fermented for four years, like fine wine but tobacco takes longer for the natural sugars to work. Then it is aged for twelve years sealed in oak barrels, like wine or whiskey, before they even consider it mature enough for blending a high quality smoke. It takes a few more years of aging for the blend to marry properly.
The tobacco I like most is about twenty years old when I buy it by the pound in sealed containers. A pound of tobacco lasts me about six months.
It is quite different for typical name brand cigarettes. Those tobaccos is mostly vacuum kiln dried and about a year old, so not matured at all ... and chemicals are added ... eewwwweee!
Cigars can be quite complicated by some being wrapped just barely older than green and matured whole for years, while others are wrapped with more mature tobacco using a specific wrap for various qualities, then finish maturing over years.
But, yes, cigars can be kept for ages if you know how.