On Twitter you get built-in liking, sharing and commenting, people will also DM you with questions, it's all one tap away. If you just post a link to a blog post, almost nobody will click it and read it there.
For example, here's the thread author quote-tweeting the beginning of his thread, which allows him to prepend both a tl;dr and a link to "archive.org/donate"
https://twitter.com/textfiles/status/1204431184069058560
If he wrote a blog post that includes the fundraising URL (e.g. at the top and the bottom) and tweeted a link to that blog post, you believe that that call to action would be more visible and obvious to the average reader?