There's a few good reasons for this.

1. Every time someone shares a Twitter link, people will click it to check the comments or whatever. With the amount of tweets still being posted here, Twitter must be getting thousands of visits just from us every day. By banning them altogether, you are significantly helping to starve the beast. It also means people won't be looking around on Twitter for shit to share on here.

2. Everyone who is saying anything worthwhile is getting banned or leaving. There's very little of value that you can't find somewhere else like Gab or Telegram. Just leftists and Ben Shapiro/Charlie Kirk types.

Look at me. We are the news now. We don't need Twitter. Even if you do want to hear from these conservative e-celeb types, if the attention dries up on Twitter they'll leave, which will further hurt Twitter. Even normies will eventually be driven away by the constant "fellow whites" and BLM bullshit on there, leaving it as a leftist cesspit.