No, it was different. It was never in the same app. Merging chat history into it was the best thing about it, and you could use it with any xmpp client (disclosure: I was developing one such client).
But it never wasted valuable screen estate in a mail app to make you know that you can also chat. There was a separate app for that.
Maybe I’m looking at the wrong screenshot, but they’re all web desktops. I assumed the previous poster was talking about mobile apps, where screen real estate is really at a premium.
The previous poster was probably talking about web Gmail where they recently added sidebar with Chat and Meet. The Gmail app, iOS and Android, doesn't have that. They did put "Chat" pane in the iPad Gmail app but seem to have removed it.
> web Gmail where they recently added sidebar with Chat and Meet
Chat has always been there though. I've used it every day for almost a decade on my work gmail account (I don't open the separate page or use a standalone client).