I moved from gears to singlespeed about 10 years ago.
End 2015 I moved from singlespeed to fixie.
Why? Because I was fed up by the narrow chains, thin sprockets, that weren't able to last 3 months without starting to skip and bicycle stores that let me wait over half a year for repair, so that my spare bicycle ran into trouble before repair was finished.
Those problems ceased with singlespeed.
The only thing left I was plagued with was the freewheel, badly sealed, causing water to intrude, in winter frost and in summer heavy rain the grease became sticky with same result.
The move gears to singlespeed went as easy as the move singlespeed to fixie. Never back. End of a couple decades returning / lasting problems and misery due to failures.
By all means: don't stay with a 3/32" drivetrain, move to 1/8".
It's really night and day wear difference.
I stayed with 3/32" the first 5-6 years, and it wore 3 chains and 1 chainring yearly. Since 2015's singlespeed>fixie (and 1/8"), I never had to replace a 1/8" chainring (alu 7075T6).
Only chains, and since end last year I started to use a version with double as thick link plates. That single chain now lasts 7 months and the chain length increase under tension sits now abit over halfway.
Some benefits of fixed gear riding:
- in winter it's much easier to stay up, both legs have support at any time
- you can save on brakes by steadily pushing against the forward movement.
- much better control / maneuverability
- the sole drivetrain limit is the frame clearance.
My daily average km is about 60-70 km.
My fixie has 62 mm tires, a 48/16 gear ratio, and my bicycles no-luggage weight (ie default weight, things I always have with me) is about 30 kg. Double big bags, a basket above them, 2 backpacks and a mountain style backpack. Tools, spare tire, spare chain (chain is the Gusset model "Tank", weights > 500 gram), and 4 small bags with cords and binders.
The biggest load I so far had, was 55 kg luggage (most parts of 4 clothes racks of 18 kg each), with 25 km to go.
The sole drawback is uphill/front wind. That's pushing at too low speed to be efficient. But that's just a fraction of the cycling time.