Only one Bike?
 

Absolutely not.

For me, I cannot imagine a worse single-bike. Maybe as a fifth bike.

For me (and I am not, you, your preferences are going to be different from mine): One bike: Endurance Road. Two bikes: Endurance Road, and Hybrid with rack and fenders. Three bikes: Add a mountain bike. Four bikes: Add a weight-weeny road bike. Five bikes: Ok, now we're at a point where I might justify a fatbike. But this is pretty theoretical; I'm pretty sure that, while I may be able to make the case for a third bike (a mountain bike), I'm never going to get #4 and #5 past my wife.

But your riding needs are totally different from mine. If a fatbike is a good decision for you, don't let me stop you.

Could you live with a Monster Truck as the basis of a one-car lifestyle? If so, a fatbike-only cycling lifestyle may indeed be for you.

I haven't owned one, but yesterday I was looking for a comfortable bike at my local bike shop (will get rid of my current one) and the owner, who had a ton of them, steered me away once he heard I wanted to ride it to neighboring towns. His basic take was something like "I'll sell you one of these if you want it, but I mostly sell them to guys who think they look awesome and want something they can have fun riding around their neighborhood on".

Right.

if you want to regain those glory days of an eight year old where your city block is your universe, fatbike will make you feel 8 again.

It depends on what your riding is. if it is off-road most of the time and only little pavement, it could work. You may look into a 2nd wheelset, like a 29+ for on-road.

For most riders, this is where N+1 comes into play. i have a fatbike and a hybrid and i can't imagine only having either bike. A bike for everything will be severely compromised. Gearing, BB height, Geometry, tire tread etc. are all specific to type of riding.

If I was riding for fun only. As mentioned, if you can live with a monster truck.
It is my 2nd bike (of 4)

For me I couldn't think of a better bike to be the one and only!!! My Farley only weighs 27lbs and was thinking of a 29+ carbon wheel set which would probably get it down to 25ish. But I decided that I wanted some squish in my life and just purchased my 1st squishy fork bike....Trek Stache 7. I love the lightness of my Farley too much to install a squishy fork....and lucky to have plenty of room for another bike.:D

I've ridden them and they do have their place, but not in my stable.

No.

Some people get the wrong impression that fat bike tires can replace full suspension for trail riding. That just isn't the case.

But maybe some like getting busted in the balls from the seat.

I'm having a good time on my fat bike, not sure I'd want it as my only bike though. I previously used a hybrid as a winter bike, and just left the studded tires on it for that purpose. Still, there is a lot of time, that those lovely Gravdals can't get me out my 1/2 mile long driveway because of the blowing snow across it. And, there are a ton of fat bike rides that I was missing out on:)

So, the fat bike allows me to continue riding local gravel like I had intended the hybrid to do, and unlike any of my other bikes, I can actually use the groomed atv/snowmobile/bike path that starts only a couple miles from my door, or the groomed fat bike trails just a half hour away. I can see getting some really nice rolling summer weight fat tires if I still want to hit the trails during the summer as a break from my usual road rides though, and it's a heck of a good workout, but in an enjoyable way, at least to me.

No, that's because the seats are up to 60 years old in my case...

And I am going on eight bikes, all of which are totally badass and Rollfast Approved (why wait for the government to do it)?

Nobody said necessary. It's just that full squish is more comfortable. Rigid beats the crap out of you if riding on rocky and rooty trails.

No.

I need a road bike. My main cycling is road, since I live in the country and, to be honest, drivers are pretty darn good around here! Granted, I have front and rear LED lighting so they can see me, and I tend to stay as far right as possible... but anyway.

As my only off-road bike? Yea. I love my green monster bike off pavement! Not a dual suspension person, nor am I going to be doing big drops or jumps anymore. Being single working in a factory (I do well) and owning my own house, I can't afford to get injured!

However, if you look up Youtuber "Old man fat bike" I do believe he only owns a fat bike (2 now). I could be wrong, but it seems that way. Cool guy, too.

If I truly am allowed only one bike, then yes. My Farley runs 27.5 x 4.5 tires normally but I believe I could get new wheels and skinnier tires for summer riding, so I would have some variety. Around here (Wisconsin) we normally have many months of snow. My road bike sees the outside roads maybe 6 months (depending on road conditions) but my fat bike can be used all 12 months, in all conditions.

Is it the ideal bike for all conditions? Oh no. I need to have my fat bike, my MTB and my road bike for the variety. When I'm riding my fattie on the roads (when the roads are snowy or icy), I miss the speed I get w/the road bike.

Yes. I ride really crummy gravel roads and rails to trails and the fat tire is great on these surfaces.I have four bikes and the fat tire gets the most use.

Any bike will roll obstacles. Some just do it better than others. Like those with suspension.

That's a negative ghost rider.
A fat bike will handle obstacles much better than a full suspension bike. It's not just about cushioning the bumps, the tires form around the obstacle providing grip.