As I said, that’s how Dark worked and Netflix took on 1899 knowing that. They knew it was supposed to be a trilogy, just like Dark. They knew it would be a mystery, just like Dark.
If they didn’t agree with that then they should have either a) not taken the project on, or b) made it absolutely clear to the writers that there was a high chance it would be cancelled after season 1 and to write it accordingly.
The expense part is purely on Netflix’s head. They wanted to invest in new technology and used 1899 as their reason/showcase. The writers couldn’t have cared less if it was a green screened boat or some weird 3D set.
Perhaps things would have been different if they had kept it in German (and in that branch of Netflix) rather than forcing it international, who knows. Let it perform accordingly for their local audience and then any international viewers are a bonus, god knows the majority of the English speaking world has zero interest in subtitles. Different cultures have different expectations from their programmes, and let’s face it, the American one is for the majority one of minimal effort and instant gratification.