Instantiating 90.000 gameObjects (very simple) takes forever and freeze unity

Hi! So I am making a WWII strategy hex game, and I am making a map of Europe (300x300) and when loading or even creating the map, unity will freeze and it is taking around 3 minutes to create the map. I don't understand how it can be SO long to create just 90.000 simple tiles. Also, it does not even really depend on the hardware because I made my brother generate a map of the same size with his high-end PC and it took the same amount of time. I want to add that the script TileGO that every tile has, doesn't have ANY Start() method or even an Update(). And I would like to add, that I have like 1FPS in game when looking at the 90 000 tiles, is that normal ? when I come closer, it is totally fine. Here is my code :

 GameObject newTile;
 
         for (int x = 0; x < GameData.GetInstance().map.SizeX; x++)
         {
             for (int y = 0; y < GameData.GetInstance().map.SizeY; y++)
             {
                 // LOADING EXISTING MAP
                 if (MapEditorMenu.isLoadedMapEditor)
                 {
                     // Check what version of the tile needs to be instantiated
                     if (GameData.GetInstance().map.TilesTable[x, y].IsWinterTile)
                         season = "Winter/";
                     else
                         season = "Summer/";
 
                     // instantiate the prefab
                     newTile = Instantiate(Resources.Load("Prefabs/Tiles/" + season + GameData.GetInstance().map.TilesTable[x, y].Name) as GameObject);
 
                     // change its material, because in game i added 2D light, but i don't want to bother with it in th editor for performances reasons
                     newTile.GetComponent<SpriteRenderer>().material = BaseTileMaterial;
 
                     //change the GO's name to its coordinates to recover it faster
                     newTile.name = x + " " + y.ToString();
 
                     // add the tileEditorGO component
                     newTile.AddComponent<TileEditorGO>();
 
                     // add the tile in unity to my mapData used for saving
                     newTile.GetComponent<TileEditorGO>().tile = GameData.GetInstance().map.TilesTable[x, y];
 
                     if (GameData.GetInstance().map.TilesTable[x, y].IsVictoryPoint)
                     {
                         // Caching the victory points to reuse later
                         listOfAllVps.Add(newTile.GetComponent<TileEditorGO>());
 
                         // set the city name 
                         if (GameData.GetInstance().map.TilesTable[x, y].CityName != null)
                         {
                             GameObject prefab = Resources.Load<GameObject>("CityNames/BaseCityNameHolder");
                             GameObject cityNameGO = Instantiate(prefab);
 
                             cityNameGO.GetComponent<SpriteRenderer>().sprite = Resources.Load<Sprite>("CityNames/" + newTile.GetComponent<TileEditorGO>().tile.CityName);
                             cityNameGO.name = GameData.GetInstance().map.TilesTable[x, y].CityName;
                             cityNameGO.transform.SetParent(newTile.transform);
                             cityNameGO.transform.position = new Vector3(newTile.transform.position.x, newTile.transform.position.y - 2.3f, newTile.transform.position.z - 1.1f);
                         }
 
                         // Add the owner's flag (Germany, USSR ...)
                         selectedPlacedTile = newTile;
                         foreach (Player player in GameData.GetInstance().listOfPlayers)
                             if (GameData.GetInstance().map.TilesTable[x, y].Owner == player.Name)
                                 SetflagForVP(player.Country);
                     }
 
                     // Destroy the original component, because this is the component I use for 
                     Destroy(newTile.GetComponent<TileGO>());
 
                     // spawning the ground unit on the air unit if there is one
                     if (GameData.GetInstance().map.TilesTable[x, y].AirUnit != null)
                         SpawnTheUnit(GameData.GetInstance().map.TilesTable[x, y].AirUnit, newTile);
 
                     // spawning the ground unit on the tile if there is one
                     if (GameData.GetInstance().map.TilesTable[x, y].GroundUnit != null)
                         SpawnTheUnit(GameData.GetInstance().map.TilesTable[x, y].GroundUnit, newTile);
                 }
                 // CREATING A NEW MAP :
                 else
                 {
                     newTile = Instantiate(baseEditorTileSummer) as GameObject;
 
                     newTile.name = x + " " + y.ToString();
                     newTile.GetComponent<TileEditorGO>().tile = new Tile();
                     GameData.GetInstance().map.TilesTable[x, y] = newTile.GetComponent<TileEditorGO>().tile;
                     GameData.GetInstance().map.TilesTable[x, y].Name = "Plain";
                 }
 
                 // assign the tile's parent
                 newTile.transform.SetParent(parent.transform);
 
                 // place the tile on the map
                 if (x % 2 != 0)
                     newTile.transform.position = new Vector2(x * 4.4f, y * 5.1f);
                 else
                     newTile.transform.position = new Vector2(x * 4.4f, y * 5.1f + 2.55f);
             }
         }