If you look around, then you will find that all of the old city builders inspired countless other games.
There are games inspired by the Ceasar/Pharaoh games.
There are games inspired by Sim City.
There are games inspired by The Settlers.
There are games inspired by Dwarf Fortress.
But where are the games inspired by the Anno series, especially when you consider the shift in design after BlueByte got the IP.
Anno 1602 was once one of the most popular games in Germany, but it seemed to have left no impression on the modern indie games industry unlike all the other examples above. Apart from Unknown Horizon, which get's one update every 2 years or so, there are no other games like that. Or does anyone know a game like that?

Define "Anno" gameplay? I haven't played them enough, but, what I did, felt very "Impressions CityBuilder" in style.

The Anno series (started in 1998) was itself inspired by the older "The Patrician" (1992).

But to try and answer your question: I believe the Anno series is simply THE top dog in the "economic sim with sailboats" segment.
It leaves no room for any competitors.

Edit: typo

Well, you build a city and provide certain goods to your citizens, after the city grows a bit, the citizens demand more different goods and you have to explore the game world for islands that offer resources to produce the goods in demand. The mid and late game usually consists of optimising the amount of citizens you can support with the resources you have and fighting the AI players for more resources and so on. I was afraid of that. The current Ubisoft/BlueByte offerings are enough to fill that niche completely. I was wondering if I just missed a game here or there, since the indie market is such an ocean of different games trying to recreate past successes.

Inspired by you say,

though most game do fit the management title quite nicely, i'm not sure what anno offers that really makes it stand out so you can say that this is an item you would want to see reproduced, or maybe a game specific mechanic you are surprised to see this not made it into other games?

Is it the way anno treats resource and population needs? Is it the setup of well thought out levels where you are forced to create huge resource chains spanning different territories?

the music?

What would you like to see in a game inspired by the anno series? what is the anno trademark that you would like to see copied

are some of the questions i'm left wondering

Lethis Path of Progress (here on GOG)?

Now, after thinking about it a little bit more, I think, I am too hung up on the aesthetics of Anno games. In my mind it felt like as long as you are not sailing from island to island, it is completely different from the Anno games I love. But looking at the core mechanics of the city building part, it is nothing that special and can be found in countless other city building and managing games.

One difference is that the required resources in anno are not in the same location, in such a way that it necessitates the use of several colonies/bases, with manual trade routes set up between them, to channel the resources to some main location.

It'd be interesting to ask what other games do this, in a way that als offers city building. Ymir on steam might be one.

in a way rail road managers have you doing the same thing, more or less

One of my favourite games, they are still a niche type of a game. They didn't invent or define a genre. So they won't exactly inspire a massive following of copycats.

And that's a good thing.

Port Royale.

get Anno 1800 it is awesome