The problem with the Lakers is that, they don't have a back-up bit for Hayes. They signed Alex Len to be the back-up big of the Lakers, but it turns out that it's a failed one because Len is a liability when he's on the court. He doesn't shoot, doesn't rebound. In short, he's inefficient when he's playing that's why the Lakers have a bad defense.
Yes, that's why the really wanted to get Williams, before, and I don't think that Hayes could really be the definition of a pure center. Although he is tall, but he doesn't have that big "presence" in the middle.
And the next big thing for them is Alex Len, but he is way underperforming that they just decided to stop experimenting with him and bench him. And it was Luka, Lebron and Reaves that are really bringing the Lakers to a win. But it could be very different if they go on the playoff and face a physical team or at least does have a good center.
They wanted him, but the problem is Williams didn't pass the physical test because of his past injuries, and how many games he played in the last 3 years. If I'm not mistaken, he played around 30% of the total games in the last 3 years which for us is horrible that's why they went to another big hence, they get Alex Len but... we know what happened before that.

As for Hayes, he's too skinny for me to be a center. Yes, he's an athletic, tall guy, but if the Lakers wanted him to be their starting center for the future, they need to develop him even more. What's good about him though is that he is playing way better ever since Luka went to LA because he's the recipient of the lob pass that comes from Luka. Anyway, if the Lakers will fail this playoffs, I'm pretty sure they will get a back-up big in the off-season. I have high expectations about them though. Maybe the highest that they can get is the 2nd round or even the Conference Finals depending on their opponent.
Guys, has anyone noticed here that after Anthony Davis is back, the Dallas Mavericks already have 2 winning streaks?
This is why I am convinced that Anthony Davis is really a key player for their lineup. Now, there will be a rematch with the Nets from their last week's match that Mavericks won by 120 - 101.
Yep, he's back, but they just lost against a tanking team like the Nets 113-109. AD is still playing on limited minutes, but the Mavericks can't afford to have losses like this moving forward. What's good why didn't went to 10th spot is the Kings also lost against the Pacers so they remained at the 9th seed. The Suns are coming though as they're only 1.5 games behind the Mavericks.