yeah a shiny with good IVs/Nature will still be a great find since that's like winning the lottery twice~three times with one ticket, no doubt about that.
it helps you get A shiney
but not A specific Shiney
It increases the market of available shinies, can more easily trade for the one you want or grind out the one you want. My point is, they aren't made worthless, but their value has indeed slipped, hence, the chain systems have devalued shinies. That's all.