Unity 2D Tile World - How to Place Animated Objects?

Question

I'm creating a 2d sandbox game (like terraria). Rather than use Unity's tilemap, I'm drawing rectangle textures to a mesh (on chunks).

public List<Vector3> newVertices = new List<Vector3>();
public List<int> newTriangles = new List<int>();
public List<Vector2> newUV = new List<Vector2>();
 
void Start () {
 
  mesh = GetComponent<MeshFilter> ().mesh;
 
  float x = transform.position.x;
  float y = transform.position.y;
  float z = transform.position.z;
 
  newVertices.Add( new Vector3 (x  , y  , z ));
  newVertices.Add( new Vector3 (x + 1 , y  , z ));
  newVertices.Add( new Vector3 (x + 1 , y-1  , z ));
  newVertices.Add( new Vector3 (x  , y-1  , z ));
 
  newTriangles.AddRange(new int[]{
  0, 1, 3, // Triangle 1
  1, 2, 3 // Triangle 2
  });
 
  mesh.Clear ();
  mesh.vertices = newVertices.ToArray();
  mesh.triangles = newTriangles.ToArray();
  mesh.Optimize ();
  mesh.RecalculateNormals ();
}


public void AddSquareToMesh()
{
...
}

public void UpdateMesh()
{
...
}

I can't decide whether to:

1. treat objects as tiles (and refresh the tilemesh 24fps when animating objects); or
2. just use GameObjects for objects.

The problem with option (1) is refreshing a mesh at 24fps makes it flicker on low end PCs. The problem with (2) is there could be 16000 GameObjects constantly loading/unloading as the player moves around. Option (2) would use a pool manager and ECS, however that rules out WebGL.