I think that this is what we’ve all been expecting, but to hear Robert Downey Jr. confirm it to Entertainment Weekly just makes the anticipation for his film all the more intense.
We basically know that the MCU will not be the same after this film and with Avengers 4 still shrouded in mystery, we don’t know how much resolution we will even get in Infinity War.
While none of us want to see our heroes die, so many films build up the threat only for everyone to escape unscathed in the end.
The world-ending threat is so common, both in other films and the MCU, that in order for the danger to feel real, there have to be consequences.