A couple of things.
Controllers handle HTTP requests. You don't call their functions directly. Also, redirect()->route() doesn't work like that - you need to pass a route name to it:
// Route definition:
Route::get('/something', [SomeController::class, 'show'])->name('some-route');
// Redirecting to that route in a controller:
return redirect()->route('some-route');
// Redirecting with parameters:
return redirect()->route('some-route', [
'my-param' => 'my-value',
'other-param' => 'other-value',
]);
I don't use Filament so I can't say if your approach is correct. But I wouldn't think you'd redirect manually like that. There's probably some built-in way to submit forms in Filament.