Ariane has always been conceived as a large carrier designed to do a small number of heavy launch to orbit several satellites in geostationary orbit.
Space X was initially designed to do a lot of small launches into low-Earth orbit.
These are two very different approaches.
In 2009 and 2010, when the main design choices for Ariane 6 were made, reusable engines were seen as too costly to develop, produce and maintain for a heavy launcher.
At that time, the scenario envisaged was to return only the first-stage engines via a glider in the same way as the Space Shuttle.
In 2009 and 2010, when the main design choices for Ariane 6 were made, reusable engines were seen as too costly to develop, produce and maintain for a heavy launcher. At that time, the scenario envisaged was to return only the first-stage engines via a glider in the same way as the Space Shuttle.
Ariane Space has only recently started work on a prototype reusable stage. https://www.esa.int/Enabling_Support/Space_Transportation/Fu...