@my_name_is_dimitris not sure I understand correctly what you want, but possible something like this:
public function index()
{
$period = range(Carbon::now()->year, 2018, -1);
$users = User::with('subscriptions')->all();
return view('index')->with(compact('period', 'users'));
}
<thead>
<tr>
<th> Name </th>
@foreach ($period as $year)
<th> {{ $year}} </th>
@endforeach
</tr>
</thead>
<tbody>
@foreach ($users as $user)
<tr>
<td>{{ $user->name }}</td>
@foreach ($period as $year)
<td>{{ $user->subscriptions->first(fn($subscription) => $subscription->SubscriptionYear == $year) ? 'true' : 'false' }}</td>
@endforeach
</tr>
@endforeach
</tbody>