LMGs are without a doubt the most versatile and effective weapons in The Division 2. The classic variant of M60 is probably the best LMG you can currently get.
Many players may skip on an LMG as their main weapon due to a very long reload time, which at times can take 5-6s. That is a lot, especially when you're in the middle of a shootout.
But M60 has an advantage over the rest of the LMGs in the game due to its huge magazine capacity and sheer damage power. This means that you will kill a lot more enemies with it and reload a lot less.