It's been a while since we've had a post outside of the contests, so let's see if this will work.

Iga Swiatek has a very large lead for the number 1 ranking (over 4000 points), but she's defending 6000 points at Indian Wells, Miami, Stuttgart, Rome, and the French Open, so if she loses early in any of those places, that lead will get whittled down.  The only players who repeated the Sunshine Double the following year are Federer and Djokovic.

Considering her opposition, Sabalenka can overpower her.  Jabeur or Bencic might be able to use their variety to keep her guessing and trouble her.  Rybakina's offense and movement worked in the Australian Open.  Osaka is out until 2024 and who knows what state she will be in when she returns.  Kreijcikova has beaten her twice in finals, so her attacking and variety strategy seems to be working the best right now, but she is also much lower in the rankings and will have some difficulty facing her (though with her winning her first 1000 tournament by beating the top 3 players, I see her in the top 5 by Roland Garros).

So, I'm thinking that she isn't really consistently challenged by anyone other than Kreijicikova for now.  Maybe that will change, but I think we can pencil her in as number 1 until at least the French Open.