Gacha is far from dead, or waning. I have been playing gacha machines and collecting them for four years now. Good people in the community, and I have a Marketplace store that nets me enough to pay my SL rent. The actual machines are the devil. You will get the same crap common five times in a row and some of the creators set it so that the rares almost never pay out. The trick is to know what something is worth and buy it at a yard sale when you see it's a bargain.
There's a lot to it, so it's hard to judge it. I will go to a creator's store if I like one of his or her gacha sets and buy more of their items. It's good promotion. But a lot of the machines are filled with crap sets, especially these days. Also, most of everything has been done so there's a ton of retreads now. But creators like Jian, 8f8, RH and Dust Bunny all have a lot of worthwhile stuff in their machines.