Every platform promises a single pane of glass. Buy four of them and you've got four single panes of glass.
The goal is right. Pulling signals into one place, so an analyst isn't hopping between ten consoles at two in the morning, is real value. Correlation across tools is where a lot of actual detection happens.
The catch is who does the pulling. Each vendor's single pane shows their own data beautifully and everyone else's poorly, if at all. The pane is single only from where they're standing. Add the next tool and its own pane arrives, equally convinced it's the one you'll live in.
Consolidation you buy and consolidation you build are different things. One is a dashboard that happens to sit on top of a single product line. The other is the work of integrating sources that were never designed to talk to each other.
So the question isn't whether it's a single pane. It's whose data it leaves out, and what it costs to feed it everything it's missing.
A pane of glass is only as useful as what you can see through it.