Gnome decided to remove the navigation feature type-ahead and replace it with search. They fail to see this is a big problem for many users.

Up until Ubuntu 17.10 Canonical provided a patched version of Nautilus that retained this feature. This is not the case anymore and type-ahead is gone for good.

You are of course welcome to join the Nautilus mailing list and state your reasons why this feature is still needed. I don't see much use in that, though. One of the maintainers told me "This has been discussed to death and we have likely heard all the arguments."