Limiting temperature change by every additional 0.1°C is not really about comfort. Either way rich people will be comfortable and poor people will be uncomfortable or dead. It's about buying everyone more time to adapt.

With respect to human lives it could mean the difference between tens of millions of deaths and billions of deaths. With respect to wildlife it could be the difference between losing 10–20% of the planet's species in the Holocene extinction versus 40% or more as per the IPCC. With respect to migration it could mean the difference between levels that are painful versus globally destabilizing. With respect to geoengineering it could mean that we have significantly more time to refine the technologies before they're inevitably deployed.

Millions fewer people will die. That’s the difference.

It’s just a sliding death scale, not a binary one. Sure, there might be steps, it might not all be linear, but still: doesn’t mean at some point doing something is pointless.