Oil lamps are much better when you don't have access to electricty or battery (no electricity would mean "solo" in your metaphor).
For once, I think the concern expressed was well explained and the thread isn't titled something like "REMOVING REACTION SKILLS, THE BIGGEST ERROR SE COULD DO". Allowing these abilities to be used cross-class (not saying cross-job since we know jobs will have have more restrictions but we don't know how) wouldn't hurt anyone and benefit the people who'd rather play as classes when they need to solo.
I used to farm solo as PGL before 1.18 versus r65ish boars with those reactive skills. It was challenging and a lot of fun, and I prolly couldn't have done it without them. Combos should be fun too, so we'll have to wait and see. And again, we just have the tip of the iceberg, there might be other things coming affecting this that we don't know of.