Originally posted by Ryzilynt:

Do some research

Exactly. It didn't start with a huge team, it still doesn't have a huge team. A quick search will find many articles, including one on IGN where I got this quote:

Svensson began development in late 2018, and Törnqvist joined in mid-2019. By 2020, the two had expanded their team to five and struck a deal with their publisher, Coffee Stain. The indie publisher, though young, has a history of strong success with co-op focused games, such as sci-fi factory simulator Satisfactory and procedural underground mining FPS Deep Rock Galactic, each of which have over 40,000 user reviews averaging out to ‘Overwhelmingly Positive’ on Steam.

As for the OP - if you can't dig down, build up. Don't want to do that? Adapt your building to the terrain and save yourself the headache of trying to get things level. I've done that and I find building much more enjoyable now.