clarification about admin role

[xlogex]

https://github.com/fullstackhero/dotnet-webapi-boilerplate/blob/1c67559e315b517bc87c7284dc686cbb9f73ff10/src/Infrastructure/Identity/UserService.cs#L106 Why you cannot remove admin role? ..... (should be not able only on root user)

[xlogex]

public async Task<bool> IsRootTenantAsync(string userId, CancellationToken cancellationToken)
    {
        var user = await _userManager.Users.Where(u => u.Id == userId).FirstOrDefaultAsync(cancellationToken);

        _ = user ?? throw new NotFoundException(_localizer["User Not Found."]);

        bool isRoot = user.Email == MultitenancyConstants.Root.EmailAddress;
        return isRoot;
    }