Normally I would say the gear range on the bike is perfectly adequate. I run a 1x11 setup on my mountain bike, with a 36t in the front and an 11-41 in the rear, but fatter tires give it more top end. I’m not sure what cadence you find comfortable, for myself, and the sake of my knees I tend to use a lower gear and a higher cadence. I was lucky enough years ago to spend a season under the management of a well-known coach, and a lot of time on rollers, this greatly improved my pedal stroke, and since then I have used higher cadences which I can still manage somewhat smoothly.

When out on the road I come across a lot of fitness riders who grind along in big gears, and seem to shift as little as possible. When I worked as a mechanic in a bike shop, I found that many riders seldom changed gears, and some never shifted them at all. A bike has a wide range of gears for a reason, and they should be used. I started riding motorcycles at 13, and use the gears on a bicycle just as I would on a motorcycle. I shift down to a lower gear as I come to a stop, then shift up through the gears as I accelerate. On rolling terrain or when doing intervals, I shift up or down to maintain my most efficient cadence.

I’m not sure how quickly you ride, or what is your usual cadence, but if you are like most riders I see (some of whom are somewhat serious), you would probably see more benefit from pedaling a bit faster than changing your chainring.

As for swapping in a new crankset, its easy as pie, you could swap in a road crank if you like, on one of my bikes I use an XTR 9000 cassette and derailleur with a Dura Ace 7800 crankset, for which you can find a huge variety of chain rings.