Virtual Reality (VR) and Augmented Reality (AR) afford new forms of work and leisure. While affordable and effective VR and AR headsets are now available, neither technology has achieved widespread user adoption. However, we predict continual technological advances and cost reductions are likely to lead to wider diffusion in society. Bridging the chasm from the early adopters to the early majority will require careful consideration of the needs of a more casual and diverse user population. In particular, it is desirable to minimise the exclusion of potential users based on their unique needs and maximise the inclusion of users in these novel immersive experiences. Ensuring equitable access to the emerging metaverse further reinforces the need to consider the diverse needs of users. We refer to this objective of maximising the accessibility and enjoyment potential of users of VR, AR and the metaverse as Inclusive Immersion. This paper reviews the research and commercial landscape seeking to address the accessibility needs of users in VR and AR. The survey provides the basis for a synthesis of the emerging strategies for maximising the inclusiveness of VR and AR applications. Finally, we identify several unaddressed accessibility challenges requiring further research attention. Our paper consolidates disparate efforts related to promoting accessible VR and AR and delivers directions for advancing research in this area.