It's not gambling or a delusion to say we must create new technologies to have a prayer of solving the problem. And of course there's no "magic pill" - we need to innovate in a thousand different ways, simultaneously.
The scale of the problem is hard to truly wrap ones head around, but it's crystal clear that voluntary sacrifice and curtailing consumption as the primary solution is a non-starter. That's not how humans work.
Also, what about developing countries? Are we going to tell them they have to consume less too? Seems unreasonable. So we're going to ask the developed world to consume less, and some of us might reduce a little bit... nowhere near the scale of emissions reductions that are necessary. Seems more like a rounding error than an actual impact.