Why select multiple is always searchable?

Select::make('roles')
    ->multiple()
    ->relationship('roles', 'name')
    ->options(function () {
        return Role::query()
            ->when(! auth()->user()->hasRole('Superadmin'), function ($q) {
                $q->where('name', '!=', 'Superadmin');
            })
            ->pluck('name', 'id')
            ->map(function ($caseName) {
                return __($caseName);
            })
            ->toArray()
        ;
    })
    ->label(__('Roles'))
    ->searchable(false)
,