There have been threads pointing out how rare kpop solo debuts are, especially from the big companies (SM, JYP, Hybe, YG), because it is more profitable now to stick to groups.
Solo artists have their negatives, but one good thing about them is that they are much easier to start up, especially if the idol is already known. This can be great for new companies because it takes years to develop trainees (with large up-front costs), and it is hard to compete for the best trainees when you are just starting. This lowers the quality of the first group and sets the company up for a downward spiral.
One obvious example of this strategy is The Black Label. Teddy needed an act to put TBL on the map in the kpop world, but couldn't use a group because the company just started (so it didn't have the mature trainees) and he was focused on Blackpink. Of course, TBL could just fall back on Teddy's name as BB/2NE1/BP's producer, but that would only get TBL so far. Teddy needed a way to establish TBL and attract top trainees for his planned next GG. He was even competing with YG, unless he wanted their rejects.
So Teddy recruited Somi as TBL's first kpop act. Now Somi is basically TBL's ambassador with how she promotes the working environment at TBL on TV and in her YT 'I am Somi' vlogs as well as her other social media. Plenty of potential trainees probably had no idea TBL existed before Somi. Now it seems like TBL is preparing for the next step (debuting a group) with their recent expansion, including hiring staff from the big 4.
P-Nation had a similar approach, but with more solo artists, before eventually debuting a group.