The catholic position ignores the Biblical position on this issue.
We do not have any injunction or example of praying to the departed believers.
Praying for the departed does them no good. Their destiny is determined at death. They either die as a Christian and will go to Heaven, or they will die as a non-Christian and go to Hell. Once your earthly body stops working it is too late.
If the catholic position were correct, then the simple thing to do would be to pray everyone into Heaven. This would completely undercut every teaching in the NT about how one comes to faith in Christ.
Rather, The catholic position ignores the Protestant doctrine of Sola Scriptura using only the Protestant Bible as the sole authority on this issue.
We do not have any injunction or example of praying to the departed believers.
The selected application of Sola Scriptura in your comment exposes its shortcoming. Not having an injunction or example in the Protestant Bible is insufficient to declare something true or false. There are no injunctions or examples of other truths you likely take for granted in the Protestant Bible either, principal among them Sola Scriptura itself, nor the Canon, with the last book in said Bible identifying all the preceding books to be included in said Bible.
Isn't that similar to what Mormons do? If I am not mistaken, they get baptized for the dead, so they can become Mormons in the afterlife, or something like that. The Bible indicates there is nothing new under the sun, so these "doctrines" have been around for many moons. My question is, what were these "doctrines" called three or four thousand years ago?