According to the marketing master class expert Torsten Muller, domain names are not owned, they’re actually on rent for a specific period.
By an expired domain, we mean a domain name whose owner has stopped paying rent of that domain upon renewal.
Earlier the domain was owned by someone else and was registered for their use.
It might have been used as a large commercial site with huge traffic or as a personal project.
Later, for any specific reason, when the registration renewal time came up, the action was ignored.