It shows both couples but it definitely focuses way more on the second couple. Bit of a shame but I also don't mind. I liked the main couple the most in the beginning because of the heavy topics Old Xian was doing specifically with them. But in more recent years I like the second couple more (because the amount of screentime they get)
I think either the author isn’t sure what to do with the first couple anymore or she just enjoys writing the second one more. Even when they are happy together Mo has an explosive personality and combined with He Tian being so eccentric it creates easy moments for comedy and tension. Jian Yi and Zhan became so mellow so most of the time it’s pure fluff. Zhan used to be more tsundere but now he just takes care of Jian Yi and barely shows any anger. I’m not saying he should but they’re so peaceful. Maybe the author got bored.
So, i stop reading it couple of years ago when second couple became the main focus while the mains were sidelined, don’t get me wrong i loved them but i hate when 2nd cp overtakes the 1st cp. so it’s still like that or we’re back to focusing on main couple.