To add, Lake's been tweeting for two years now about every 2020 election conspiracy she comes across. Wendy Rogers used to be her Twitter buddy until the Republicans told her she had to stop associating with a complete lunatic on Twitter and be more careful about which stuff she retweeted if she wanted to be Governor. Hobbs would have to be able to respond to every single one she might bring up or Lake could make it look like she's being shady. Lake says the CyberNinja's audit found that a Chinese helicopter airdropped in a bunch of Biden ballots that were then assigned to Civil War veterans or asks why it took six hours to count some ballots instead of four hours because this is supposed to mean something to MAGA, Hobbs can't just keep saying "that's absurd and false" because every one of those claims will put the burden on her to assure the public that nothing was wrong with 2020 while Lake can gish-gallop to claim after claim that something, anything, was wrong. Lake won't look insane to people who don't know about any of this, she'll look informed and in command of the facts. "Oh, she got a few things wrong, she just was trying to be thorough about an important issue." Are you going to trust the media to run with "she said all this insane stuff and Hobbs refused to acknowledge it" or might it get paired down to "Lake raised concerns which Hobbs dismissed"? We all like to think we'll shut down any shit in a debate but especially in a timed one on TV you have to consider this kind of thing. (This is why it's often true that many candidates, not just Trump, think they absolutely crushed a debate no matter what because they assume the "relevant" audience will be on their side. See also: their obsession with how much time they get even though every single answer might potentially backfire or only serve another candidates interests.)
There's also how Lake could make demands of how Hobbs conducts herself in this election and put her on the spot. Lake has been retweeting people showing a picture of Hobbs, as Secretary of State, doing her job and implying she's up to something nefarious with the ballots because why else would she be in these locations? Okay, sure she's Secretary of State but as a candidate she clearly shouldn't be acting as Secretary of State if it benefits her. Same kind of innuendo Abrams has used against Kemp for four years. In a single debate on TV it'd be hard for Hobbs to refuse to accept anything Lake demands that could sound reasonable to people who have no idea what Hobbs may or may not have to actually do or even can do.
Normally, I'm also inclined towards debates but I think this, like some of Biden's choices in 2020, was a reasonable maneuver out of a trap even if Hobbs winds up losing.