I'm just going to make this quick and short. This idea that the thumbs-up emoji is "too old" is frankly stupid and preposterous, and let me tell you something, all of that is coming from ME, a Gen Z-er. The reason why I think this is ridiculous is because I know A LOT of Millennials who still use this emoji, and the Millennial generation (or Generation Y) came RIGHT BEFORE Generation Z, so no, the thumbs-up emoji is not that old, considering that emojis by themselves are not even that old as they were created in 1999!
Emoji Source: https://scratch.mit.edu/projects/516972176/ Just FYI, I have nothing against the people who think the thumbs-up emoji should be cancelled, but that doesn't mean I can't criticize the "it's too old" excuse.