Unity: Even when the "player" game object gets destroyed, the text doesn't appear

Question

I've been using Unity to create a simple 2D game but the problem is that even when the game object "player" gets destroyed, the gameobject "isDead" (text) doesn't appear.

This is my script.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class youDied_Text : MonoBehaviour
{
    private Transform player;
    private Text isDead;
    // public static bool isDead;
    // Start is called before the first frame update
    

    private void Start() {
        isDead = GetComponent<Text>();    
    }
    void checkForDeath()
    {
        if (player==false)
        {
            isDead.gameObject.SetActive(true);
        }
        else
        {
            isDead.gameObject.SetActive(false);
        }
    }

    // Update is called once per frame
    void Update()
    {
        player = GameObject.FindWithTag("Player").transform;
        checkForDeath();
    }
}

This script is attached in the text which I need to display in UI element.