To get scheduled tasks in system. Tested in Laravel 6+.

ScheduleListCommand.php

<?php

namespace App\Console\Commands;

use Illuminate\Console\Command;
use Illuminate\Console\Scheduling\Schedule;

class ScheduleListCommand extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'schedule:list';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'List all scheduled tasks';

    /**
     * Execute the console command.
     *
     * @return mixed
     */
    public function handle()
    {
        $schedule = app(Schedule::class);
        $events = collect($schedule->events());

        $allEvents = [];
        foreach ($events as $event) {
            $allEvents[] = [
                'cron' => $event->expression,
                'command' => $event->command,
            ];
        }

        $this->table(
            ['Cron', 'Command'],
            $allEvents
        );
    }
}