The attached flyer explains the benefits of testamentary trusts.
All of the benefits continue to apply, particularly from an asset protection perspective, even if the only initial beneficiaries are adult children.
Indeed there is also ongoing tax planning flexibility (eg streaming income and using corporate beneficiaries).
Further, if the adult children decide to have children themselves, then there will be access to the excepted trust income regime (where infant children are treated as adults for tax purposes).