In my opinion there's just not a huge demand for live singing anymore.
The landscape of kpop has changed and these days it appears more important—at least for a lot of people—that doesn't visibly suck at something rather than that the idol actually doesn't suck at the thing in question.
(I guess the reason for this are changes in popular ideas and ideals in online fan spaces combined with the global explosion of kpop combined with the Korean situation of kpop changing too combined with Tiktok's rise in popularity where toxicity spreads twice as fast as anywhere else.) A dance hole is harder to hide, so most 4th gen idols are at least above average dancers even if they lipsync all the time. Not being able to rap isn't an issue, it never has been... "Bad" visuals—which imo don't really exist and the insane standards idols are being held to are often rooted in rather problematic ideas—are also more difficult to hide, because highly invasive procedures such as jaw shaves are easier to expose these days thanks to social media and most people want idols to be more or less natural beauties.
Not being able to sing live is the easiest skill hole to hide to create the appearance of a perfectly polished idol, and therefore it's the one companies compromise on.
LAR became ridiculously widespread in the last 2 years, and it has evolved a lot since. I remember a few weeks ago or so I was watching some year-end/award show(?) and there was a gg, who really shocked me, because they weren't just using LAR, their LAR track had a compression effect added to it so it would sound like those distinct compressors on mics that normally aid actual live singing. Crazy. And it was odd cause—like normally with LAR—you could tell it was fake when the breathing didn't change between intense and less intense parts of the dance...but most people don't bother to look into those things anymore. So they have their flawless all-rounders whom other kpop stans can't drag for sucking.
It sucks because imo lipsyncing always impacts the group's stage presence negatively...and it's just so much less interesting (for instance, I like that SKZ often deliver the same lines differently and that they sometimes sing the backing vocals or change their rap flow a bit to suit live performances).
Well, even Stray Kids have their fair share of pre-recorded stages, but they indeed have quite a lot of live stages as well
To be fair stages with pre-recorded vocals are basically negligible next to the amount of live stages, they usually only pre-record if they absolutely must, Chan even explained that on a live once. Such as their performance on the wet helipad that should've never been allowed in the first place, or the time they had a special performance video for an award show where they had to do several takes throughout the day.