[Maédhros]

The men in Beleriand had no problem dying, there was no revolt against elves. Men would accept their gift accordingly, and with war going on. Why then would they not live harmoniously with the elves and Valar in Aman?

I think that the difference would be time in Valinor.
From Morgoth's Ring: Aman

The unit, or Valian Year, was thus not in Aman related to the natural rates of ‘growth’ of any person or thing that dwelt there. Time in Aman was actual time, not merely a mode of perception. As, say, 100 years went by in Middle-earth as part of Arda, so 100 years passed in Aman, which was also a part of Arda. It was, however, the fact that the Elvish speed of ‘growth’ accorded with the unit of Valian time † that made it possible for the Valar to bring the Eldar to dwell in Aman. In one Valian year the Eldar dwelling there grew and developed in much the same way as mortals did in one year upon Middle-earth. In recording the events in Aman, therefore, we may as did the Eldar themselves use the Valian unit, though we must not forget that within such ‘year’ the Eldar enjoyed an immense series of delights and achievements which even the most gifted of Men could not accomplish in twelve times twelwe mortal years. Nonetheless the Eldar ‘aged’ at the same speed in Aman as they had done in their beginning upon Middle-earth.

But since Aman was made for the Valar, that they might have peace and delight therein, all those creatures that were thither transplanted or were trained or bred or brought into being for the purpose of inhabitation in Aman were given a speed of growth such that one year of life natural to their kinds on Earth should in Aman be one Valian Year.

For the Eldar this was a source of joy. For in Aman the world appeared to them as it does to Men on Earth, but without the shadow of death soon to come. Whereas on Earth to them all things in comparison with themselves were fleeting, swift to change and die or pass away, in Aman they endured and did not so soon cheat love with their mortality.