Having used both Scala and Go for the past 6 years, I can tell that for the purposes of creating a database backed web API, they're definitely not at the same level of complexity.
This isn't about the type system. This is about complicating things by making everything FP while getting nothing in return.
That's the great thing (and the point of many of the comments in this thread) about Scala - you don't have to do any FP with Scala if you so choose. You can operate in a completely OO fashion and gain all of the benefits of the language (primarily the type system) for free.
People promoting this view fail to understand that people work in teams and it only takes one FP zealot to force everyone to do FP and your PRs don't get merged unless it's idiomatic Scala.
This isn't about the type system. This is about complicating things by making everything FP while getting nothing in return.