I run in stereo as I use IEMs and find a mono mix incredibly uninspiring. However, FOH is whatever the sound man chooses.
If I'm playing as a party band, the purpose is to please the customer therefore playing the right songs well, creating a good ambience and being the right volume is everything.
If I'm playing in my originals band, keeping it tight, energetic and clear is everything.
Stereo guitar just isn't a factor for me.
I don't find that stereo guitar effects serve anything but my own needs, certainly not to 90% of the listeners. I've even moved away from extensive use of stereo guitar tracking in recordings (i used to double track most guitars and use stereo delays more than mono). Sure, it sounds amazing on headphones but I think it often detracts in less than ideal listening positions. Not that i don't use it, just a lot less. My mixes sound less exciting on headphones now but I think they sound way punchier and clearer.