I think nitro, (compressed nitrogen used to make a drink bubbly instead of compressed carbon dioxide) is a marketing fad. Beer is naturally carbonated from brewing, and most beers don't need added compressed gas to make them bubbly. (Are there any?) It may be true that stouts might taste different with a nitro head, but I wouldn't know.
Guinness adopted the current system of delivery using a nitrogen gas mixture in the very early 60's... pretty long lived for a fad.
The few bar managers I know just experiment to see how a beer might taste on nitro.
(I suppose as coffee places sell/try flavored coffee) It's a bit of marketing too, women tend to like the smoothness that nitro lends to beer.
Some craft bars experiment with a Randall device to add a different hop.
It's true that beer is naturally carbonated, but most of the carbon dioxide is allowed to escape during fermentation. So either natural and forced carbonation is used.
Off the top of my head I remember a few bottle conditioned beers (sure there are others)
Sierra Nevada Pale Ale...... Brooklyn Brewery Local 2.... a Chimay, I don't remember which one.... Dog Fish 75 Minute is done in the big bottle
In coffee, I think added nitro is a novelty. I don't think I've ever seen naturally bubbly coffee. Espresso does have a head because it is brewed with very high pressure (about 10× atmospheric pressure) with very hot water at higher than 212°. When the espresso comes out into the cup, that high pressure falls to normal pressure, and all the dissolved gases come out of solution, making the frothy head – the crema.
I'd try a nitro cold brew before passing judgment.
The nitro adds that crema that that regular cold brew lacks.
Nitro coffee doesn’t taste carbonated, but the tiny bubbles of nitrogen make already smooth, chocolatey cold brew even smoother. It’s refreshing and seems to taste sweeter, with a textural creaminess.
I don't drink as much hot coffee in the summer, so the cold brew is just the thing when it's hot out.
Enjoy one!