In more recent years, color hosers are fewer, weaker, and more situational, and part of that is that some of these older cards simply make it so that one person cant play Magic at all, which isnt exactly fun, as pointed out by Patrick Sullivan
Mana Echoes seems like a great card to include in a Morophon deck since Morophon will often pay for colored part of your casting cost, and then Mana Echoes will generate colorless mana to pay for the other part of your Elementals casting cost, potentially letting you cast giant Elementals without much mana at all
It's a +1/+1 win con, but it's red which is harder to add in the 99 since most +1/+1 counter caring leaders aren't that color, and then only shoots one dork not all of them, so it's a bit slower
What does Rise of the Dark Realms do