Django nested subqueries extremely slow

Question

I'm working on a project in which users can have one profile, each profile can have many accounts, and an account can have many payments. The important parts of the models are the following:

class Profile(models.Model):
    username = models.CharField(max_length=250)

class Account(models.Model):
    profile_id = models.PositiveIntegerField()

class Payment(models.Model):
    amount = models.DecimalField(max_digits=8, decimal_places=2)
    account_id = models.CharField() # An unique id for the account the payment belongs
  

I have to create an annotation in the Profile model with the Sum of the amounts of all payments from that user to manipulate this data with pandas afterwards. I managed to create a QuerySet using nested subqueries to get the job done, but this operation is extremely slow (slower than iterating through all of the profiles to calculate this value).

Here is how I did it:

payment_groups = Payment.objects.filter(account_id=OuterRef("pk")).order_by().values("account_id")

payments_total = Subquery(payment_groups.annotate(total=Sum("amount")).values("total"), output_field=models.DecimalField())

account_groups = Account.objects.filter(profile_id=OuterRef("pk")).order_by().values("profile_id")

accounts_total = Subquery(account_groups.annotate(total=Sum(paymments_total)).values("total"), output_field=models.DecimalField())

profiles = Profile.objects.all().annotate(account_total=acount_total)

What in this code is making the subqueries so slow? I have done similar subqueries before to get the sum of fields in a child model. I know that doing this in a grandchild is more complex and requires more time but it shouldn't be that slow.

Is there a way to improve the efficiency of this operation?