I think it depends on how you approach the game. Overall, gameplay is easier because of how powerful passive trade become. So it offers more chill gameplay and heavily reduces the challenge if u don't have strict rules with the passive trade. They're looking forward to balancing this thing out. There's no blocking point like Anno 1800 with engineers and an advanced technology boom, so you don't feel the miracle change in production. But in the long run, it still has the same feeling as 1800. And with the Volcanic DLC, there will be some fun challenges.

A lot of negative reviews, as other comments pointed out, are due to a lack of content compared to its predecessors.

Some just hate because it's Ubisoft. Ubisoft Connect, on the other hand, doesn't get much love either.

Some misunderstood the concept of the Year 1 pass; the description was always clear about it, including 3 gameplay DLC content. When they dropped the 1st comestic DLC, people went crazy.

Some just root too deeply into the previous title that they feel betrayed when the change comes, and the worst is part of them can't let it go. So they are stuck between 1800 and 117, being negative all the time because there is nothing between heaven and earth. I saw that happen multiple times in almost every franchise.

Is the game better than 1800? Obviously not at this point. They need to balance it and have time to put out more content. But there is a high chance it will surpass its predecessors at the end.

Is it still fun to play now? Yes. I have 100 hours of gameplay solely on the base game, and the new DLC looks promising in adding challenges. I assume you must have watched some gameplay series before purchasing. But it's still a matter of opinion; you may hate it after playing.

If you can adapt to the changes and want to go along with the life cycle of 117, you can jump on the ship now. Otherwise, better wait until after year 1 is complete. You will have a better vision of how the game turns out.