Ok. So what you have is not a road bike with skinny 23 tires. I mention this because how much improvement there is depends on where you are starting from.

If you were in an aero tuck pushing high teens/low 20's deep dish aero would definitely make sense. As would low spoke count and uber light weight carbon.

That is not your case. You are largely upright, on fat tires intended for rough (or "not smooth" as will likely be pointed out) terrain.

While it is true lighter wheels "feel" faster and more responsive than heavier wheels. Heavier wheels tend to act like a flywheel and after taking effort to spin up, tend to hold momentum.

Rim & tire are seperate things. A rim is expensive to change. A tire & tube actually has a larger effect because it accounts for more more mass further out on the gyroscope. Furthermore inflation pressure & sidewall stiffness/flexability effect rolling resistance. Then there is actual friction between the tread pattern (or lack thete of) and the terrain.

My thoughts are: Before going the whole hog, sit down and really think about what your requirements are. Aero? Durable? Light? Strong? Are you going to be doing high speed downhills on washboard logging roads with loaded panniers? Are you going to do do spirited club rides to the local bakery?

If it were me, before buying new wheelset, I'd get some lighter weight tires & experiment with a range of inflation pressures. If the bike is still a dog, then new wheels always come up around November-January at a discount. AND you already have decenr rubber to make good use of their potential.

Used wheels are always available at the usual want-ad messege board places.

The hardest thing to swallow though is new wheels, tires, etc...almost never live up to the performance hype unless you are going from one extreme to another or talking extremes of minutia like single digits of watts or seconds over 10's of kilometers.

That being said: New tires/wheels will almost universally make the bike more enjoyable to ride. So on that, I say go enjoy!