When to use booldefault vs boolplanmodifier?


When I started using the new terraform framework I needed to set a default value for different attributes (strings, booleans etc) and I ended up (I can’t recall now how) implementing the setting of a default value using plan modifiers.

I’ve since discovered a simpler way using the <T>default packages (e.g. booldefault, stringdefault etc).

So, my question is: what’s the difference and why/when should I use one over the other? as they both seem to do the same thing.

EDIT: I’m still using a plan modifier for the use case where I have a fully computed attribute and I can reduce the “known after plan” message. So in the following example, once a “Service ID” is generated, it never changes…

"id": schema.StringAttribute{
	Computed:            true,
	MarkdownDescription: "Alphanumeric string identifying the service",
	PlanModifiers: []planmodifier.String{
		// UseStateForUnknown is useful for reducing (known after apply) plan
		// outputs for computed attributes which are known to not change over time.