While emoji may seem trivial, I see no reason why it shouldn't be standardized. It is a widely used method of text communication with a large number of common symbols.

Lots of writing systems that humans have invented are pretty bad, and their digital implementations are sometimes even worse, but Unicode has to live with all of them.

Before emoji were in Unicode, it was difficult to display Japanese e-mails correctly on anything that wasn't a Japanese mobile phone.

I think what emoji symbolizes is the failure of not having a ubiquitous format for rich text. Ideally you'd embed custom smily graphics. See also how people abuse mathematical symbols for "bold" or "italic" text.

I think standardization opened a whole new way of communication but yeah some parts are messed up

The alternative would be (almost) everyone just using the font with most emoji in order to support messages from other platforms, so sort of a standardization that nobody can rely on. I don't see how that's preferable.

Unicode has more than enough space and text is rarely a blip on the amount of traffic carried on the internet, emojis are fine.