@33mhz Not at all. If someone on Twitter liked your tweet and took a screenshot, that still exists. And can be replicated. Or maybe it was crawled by archive.org before you deleted it. Or maybe someone reposted it, and it got crossposted to their Facebook page, or they used one of those services that creates an RSS feed from Twitter and it's now in someone's newsreader.
Meanwhile, on Mastodon, I can delete a post. Whether it's been propagated elsewhere is basically the same situation as with the tweet in the example--it lives on beyond my control. I can't be bothered to worry about that.
We can talk all day about how the world should be, and maybe someone somewhere is working on a way to change it, but for now, it's the world we live in, and I make my choices based on that.