Guess that's good, but as others have said I have a Granny Gear so I just need to build my endurance although m really really old! Mountain biking is very strenuous depending on how hard you push yourself. I get winded and then just take a break or walk for a bit and then ride. I give it my all!
I have 22/36 with 26" bike, that is 0.65 ratio or so.
It is really nice when you have to do lot of mud, roots and rocks when climbing, walking surely is faster, but also very boring compared to slow climbing.
However even after 6 years riding, I find 22/36 being still heavy for me when climbing in such conditions, but what is limiting me is my heart rate, it hardly ever goes above 160 and it has been like that all those 6 years.
I don't have issues when I can spin, but brute force it where it gets old fast, maybe it is the age thing, but also 200lbs in muddy climbs or in snow, that is just asking for trouble if trying the force method.
I can hold 145bpm average for 2 hours though and that is not even very difficult for me, so I would say fitness might not always be the answer, depends from many variables of course and only you know your rides and fitness.
However I will try 0.71 ratio for a while, might limit where I can ride, but it is easy to put smaller chainring if needed, just need to order parts and build everything together.