Don’t know if this ever got a satisfying answer.2. The events take place in one day. In one day, Thanos collects five stones. Yet, he has been searching for them for decades and, at the minimum, he has been conquering planets for twenty years at the minimum. If the stones were that easy to find, as they were located in one galaxy, why did he not find them sooner?
Thanos knew where to find most of the Stones but didn’t have a fully functional gauntlet before. With the destruction of Asgard, Nidavellir became vulnerable and Thanos’s job got a lot easier. He went to Nidavellir, forced Eitri to make the gauntlet, and then went about collecting the Stones.