Hmm I feel this might just be nostalgia at play. I've not played any Anno games, but comparing the two side-by-side and 1800 looks leaps & bounds better to me. 1602 looks like it was drawn in MS Paint.
Of course it does :) The two games are decades apart and 1800 was known to require quite a beefy PC to run good when it came out.
My point was 1602 holds up visually in a sense of doing it’s job assisting the game mechanics, something most modern games often fail and over complicate. Also.. nostalgia.
Can you expand on that please? (I recently prototyped a maze editor in isometric view and would love to hear more about the alternatives and what makes the isometric projection interesting.)
IMO for a significant amount of games, isometric is the best way to display them as it emphasizes the dimensions of things, makes for a clear navigation and general awareness of what's going on.
Also not really an issue these days, but I think it's still somewhat valid: In a controlled isometric projection where the angles are fixed, you can focus on making the art just pixel perfect, shadows and lighting being also a big part. This makes it possible to make your game look good with a fraction of the budget. In many cases, depending on the style, you still want to model and render the stuff in 3D and use hugely advanced renderers ( now GPUs/game engines have realtime ray-tracing, global illumination, subsurface scattering, advanced shadows, etc. but still, you can get most of the look by rendering it offline and just present sprites in a "2.5D" isometric projection and they'll look amazing at a fraction of the cost for both a game studio and the gamers who have to run that )
Of course there is also a great deal of nostalgia, but I would not discount the current trends of "going back to the basics" as just "nostalgia".