That's because developers making websites don't want to bother to test their thousands of lines of application code on a bunch of different browsers.... is your argument that Threads will join the fediverse and then people arent going to test whether their 150 characters of text will work with Lemmy before posting and then all us Lemmy user's are going to quit because it's simply too much for Lemmy to render 150 characters of text and maybe an image?