When I was using VR a lot I just kind of stopped looking with my eyes outside of a small area around the middle and mostly used my neck. When looking towards the edge doesn't look great I think most people adapt and just start subconsciously working around the limitations. Maybe it partially comes from being a glasses wearer almost all my life (since around 7-8) so my vision is already basically useless for detail around the edges but it wasn't a huge jump for me.
In practice, people don’t make incredibly long saccades. Instead, there’s some coordination so that the neck or body movements do the bulk of the work.
