Every new generation of actors/actresses and scriptwriting gets progressively worse imo. Not just now, but since many years ago. I think this is the case for many countries, not just Thailand.
I started watching lakorns around five years ago. My first lakorn was RLSR with Push and Lily. I enjoyed it back then and began my forage into lakorns, mainly 2010s lakorns. Then I started watching lakorns from the 2000s because I got bored and realised I found them much more enjoyable than the ones from the 2010s. Started watching 90s lakorns and I feel that those ones are better than the 2000s ones (even without subs). The more I get into older lakorns, the more unwatcheable the new ones become. It's not always the case, but I've noticed that when I watch the newest remake of a lakorn and then watch the old one, I can't stand the new one anymore.
I feel that older lakorn scriptwriting is more romantic. Nowadays, to show that the p'ek is in love with the n'ek, they tend to just make them get jealous or make them get super worried when the n'ek gets hurt. It's pretty much flat-out telling the audience that p'ek loves n'ek because it's so typical.
Compare that to older lakorns like Ruk Jiow Kong Jenjira (Willie/Joy). There's a scene where Joy has to leave Willie's house and his niece is crying and holding onto Joy's hand. Willie pulls his niece's hand away and whilst doing so, runs his pinky down the length of Joy's hand for sneaky final touch before she leaves.
In Dome Thong, Tua nonchantly gives Nampeung a gift, coolly telling her to just accept the gift when she questions it. But you'll notice that the entire scene he avoids eye contact with her. He even gets up from his desk and has his back facing her as he continues to talk because he is embarassed.
It's these little mannerisms/actions - Show not tell, that I find lacking in current lakorns. It is probably a mixture of both scriptwriting and the actors ability.
I've been reading comments from chinese lakorn fans who have recently begun to watch 90s lakorns (after watching the remakes) and there seems to be a general consensus that, while they enjoyed the remake first, they're finding the older version more beautiful and elegant. The actors more charismatic and the actresses more gentle and lovely. What's funny is that they call the older actors uncle in chinese. Like Sam叔, Tua叔, Willie叔, Nok叔.