(It's only my opinion, you are free to feel different about it.)
I'm currently rewatching and reviewing the 1981 series and I've just started the Season 3, while I also saw the first episodes from the new Season 3, and I've been comparing them for the past few days and all I can say is that the Smurfs went downhill. It is losing the charm of the Smurfs the old series managed to capture.
To be honest, I really don't like the new season. Firstly I hate the new characters. Rowena is annoying and Dwayne, as I've seen so far, has no real personality other than just being a generic spoiled kid. As for Bubble and Firefly, they shouldn't have abilities. It ruins the Smurfs, I'm sorry.
It has so much potential as it introduces the girls village, but we're already seen one third of this season and only 30 seconds of the girls' village. Instead, it focuses mostly on badly personalized characters and is not written that well.
Gargamel has become a joke, as the Smurfs such as Hefty or Storm or even Lily easily and fearlessly pick on him like he was not supposed to be the biggest threat to the Smurfs. (There is also a scene from "His Own Worst Enemy" where they beat him with dancing but it's so horrible I seriously don't want to discuss it.) Azrael has just disappeared, his screentime and importance was reduced too much and overshadowed by the new kids, even though he's supposed to be the second most important antagonist, who always comes alongside Gargamel.
It's hard to write original plotlines, as the 1980s series has already explored a lot of ideas, so we are getting episodes such as "The Great Smurfs Games", which is a modernized version of "The Smurfic Games", or "Dragon Pet" having the idea of "Master Scruple". They also seem to remake their own ideas, like "The Tour" (horribly unoriginal title by the way), which seems to be exactly like "Unsmurfable Smile".
The action hasn't yet moved out of the Smurf Forest (except for the poor scene in the girls' village) and the lack of location diversity is a bit frustrating to me, like there's nothing outside the forest, even mountains you can see in some shots are just there.
A lot of time in the episodes is filled with pointless dancing and running around, or overly long fight and conversation scenes. Most episodes with great potential such as "Dragon Pet" were made really badly and for me felt hard to watch, even if they include some good jokes. I was really disappointed after I saw the execution of not that bad main ideas.
The episodes also don't use enough ccharacters in my opinion, that's why I very much dislike those like "What a Doll". This is also somehow connected to the story quality, as the focus is on a constantly on a small amount of characters and there's no room for supporting roles.
Personally, I really only enjoyed "The Ultimate Prank" (though it's very unllikely for Papa to cooperate in the whole thing), "The Tree of Knowledge" or whatever they'll call it in English (because it's based on the idea of everyone seeking for Papa's advice), "Reaching for the Stars" (I'm not sure why, I find it wholesome), and I'm also fine with "Magic Meltdown".
It might seem like I hate the girls (althogh I think they ruined the original idea of the Smurfs with their introduction, I still find them interesting), but most of their episodes are poor and not very entertaining, and we don't have enough Smurf girls, so it's also a diversity problem.
I'm going to review all the episodes individually some time, but I already mentioned that I'm currently doing the 1980s Season 3, so probably I won't reach this season in a few months.
That smurfs it.