The main issue with IaC is most of the IaC tools (looking at you Terraform) actually want to do Infrastructure as Data where everything is completely static. So you will quickly run up against multiplying complexity as you try to DRY things or even just dynamically configure things with tools that are philosophically opposed to you doing that. Eg: want an optional component deployed for test environments? you are treating it as an array of them where the count is zero or 1 and this will ripple through everything as awkward syntactic distortions and bugs everywhere.

I would like to use tools like Pulumi but it seems for now the IaD people are winning the mindshare battle.