There's a reason that AAA open-world games like GTAV are using rather limited procedural generation, too.
The problem is that to create N pieces of satisfyingly unique procedurally generated content, you need M pieces of content that were carefully designed within additional restrictions to make them combineable in various fashions - making them harder to create. Then you add code to glue that all together. If you think M=0, that just means you've hardcoded your content in code.
When N >> M - e.g. you're generating thousands of similar-yet-distinct roguelike levels, trees, etc. - procedural generation can pay off.
But even for large-scale world assets, it's frequently the case that N < M. Making the content non-procedurally is going to be cheaper - fewer limitations to worry about, and fewer pieces of content to actually generate. A few clever tricks - rotating, retexturing, tweaking a base model, etc. - let you make a lot of non-procedural content without creating each piece from scatch, and lets you stretch that content to appear like you have more variations than you actually do.
The problem is that to create N pieces of satisfyingly unique procedurally generated content, you need M pieces of content that were carefully designed within additional restrictions to make them combineable in various fashions - making them harder to create. Then you add code to glue that all together. If you think M=0, that just means you've hardcoded your content in code.
When N >> M - e.g. you're generating thousands of similar-yet-distinct roguelike levels, trees, etc. - procedural generation can pay off.
But even for large-scale world assets, it's frequently the case that N < M. Making the content non-procedurally is going to be cheaper - fewer limitations to worry about, and fewer pieces of content to actually generate. A few clever tricks - rotating, retexturing, tweaking a base model, etc. - let you make a lot of non-procedural content without creating each piece from scatch, and lets you stretch that content to appear like you have more variations than you actually do.