252+ SpA Life Orb Sheer Force Xerneas Thunderbolt vs. 252 HP / 252 SpD Kyogre: 229-270 (56.6 - 66.8%)
252- Atk Life Orb Sheer Force Xerneas Bolt Strike vs. 252 HP / 252 Def Kyogre: 367-432 (90.8 - 106.9%)
I think this is important enough to consider Bolt Strike on Sheer Force Xerneas.
Look at another "safe switch-in" to Xerneas:
252- Atk Life Orb Sheer Force Xerneas Bolt Strike vs. 248 HP / 252 Def Darmanitan-Z: 165-195 (39.9 - 47.2%)
252+ SpA Life Orb Sheer Force Xerneas Thunderbolt vs. 248 HP / 252+ SpD Assault Vest Darmanitan-Z: 86-101 (20.8 - 24.4%)
And this is with Modest nature.
Fair point, but you also need to look at walls who are lopsided in the other direction.
252- SpA Life Orb Sheer Force Xerneas Thunderbolt vs. 252 HP / 252 SpD Flashfire Mega Aggron: 136-161 (39.5 - 46.8%) -- guaranteed 3HKO
252+ Atk Life Orb Sheer Force Xerneas Bolt Strike vs. 252 HP / 252 Def Flashfire Mega Aggron: 112-133 (32.5 - 38.6%) -- 98.1% chance to 3HKO
Adamant against a FF user, so Blue Flare wouldn't work here.
252 SpA Life Orb Sheer Force Xerneas Thunderbolt vs. 252 HP / 252 SpD Flashfire Mega Scizor: 133-156 (38.6 - 45.3%) -- guaranteed 3HKO
252 Atk Life Orb Sheer Force Xerneas Bolt Strike vs. 252 HP / 252 Def Flashfire Mega Scizor: 151-178 (43.8 - 51.7%) -- 10.9% chance to 2HKO
Neutral nature against another FF user. In this instance, the 15% chance to miss and reduced PP isn't worth the 10% chance for a 2HKO, which wouldn't happen regardless if Scizor is a physically defensive nature or Xern is using Modest/Timid.
Again, depends on your team's needs. It's not a clear cut "X is strictly better than Y in all non-niche situations". If you feel Bolt Strike would suit your needs better, use Bolt Strike. If Thunderbolt suits 'em better, use Thunderbolt. If you'd rather have Thunder's power and don't care about the acc, use Thunder. If your team needs, say, Ice Beam, Dark Pulse, Earth Power, or another move more, then use that over Thunderbolt/Bolt Strike.
Edit: The same argument could be made about my choice of Blue Flare vs. Searing Shot, Flame Thrower, or Lava Plume. Though