First of all, you can win 1 because infinite gems have great side effects, and because these six gems are products of heaven and earth, you must pay some corresponding prices if you want to use their power. Therefore, after Thanos snapped his fingers, his whole arm was abolished, so as to destroy this gem and completely destroy his body.
Doraemon, on the other hand, has no side effects, although there may be some defects in the number of uses. In the process of fighting against Thanos, Doraemon can use a time machine to cross at will, unlike a time gem. He can collect all those gems before Thanos, so that Thanos can't find them or put them in other time and space.
So if Thanos plays Doraemon, those endless props of Doraemon can defeat Thanos.