Is Chrome the New IE? (2023)

No not even close by every single possible measure.

I was there, I suffered through it, Google would have to make TONS of hostile moves for that fact to change.

I have no interest in the arguments of a closed source subscription service that wants me to switch to the bundled browser of the wealthiest company on earth's most popular consumer OS, lecturing me about using the 4th wealthiest company on earth's browser that I freely installed.

The most important one from an anti-trust perspective, every device I've ever had Chrome on I've had to seek out and install/make default Chrome, that includes my mobile devices which used the manufactures browser by default.

If I want to use chromium I can, Safari has been VERY late in implementing certain industry spec standards (SSE's, web sockets, IndexedDB API, animations, relative color syntax, container queries, a bunch of <video> stuff, flexbox, the list goes on and on.)

It definitely is, I was also there, just like everyone was doing IE only sites, not only plenty of people do the same with ChromeOS vision of the Web, they ship Chrome alongside Electron crap.

Safari is the last man standing before a ChromeOS world.

Considering Safari is mainly used on a platform where it's mandatory, I'm not sure "standing" is the term.

Last man being propped up Weekend-at-Bernie's style?

It’s not really mandatory, you can use other browsers on both iOS and macOS

Except you can't. Every browser on iOS uses Safari's rendering engine. Chrome/Firefox on iOS are effectively reskinned Safari. This is an apple requirement. The rendering engine being the important part here when talking about standards and such.