Investigate large memory usage

Nobody has claimed this yet.

## Description of bug / unexpected behavior
The following scene:

```py
from manim import *

class Frac(Scene):
def construct(self):
tri = RegularPolygon(n=3, fill_opacity=1, stroke_opacity=0, fill_color=GREEN)
tri.scale(2)
a, b, c = tri.get_vertices()
tri.scale(2)
self.play(FadeIn(tri))
for it in range(7):
A, B, C = tri, tri.copy(), tri.copy()
if it == 0:
B.set_color(BLUE)
C.set_color(RED)
self.play(
AnimationGroup(
C.animate.move_to(c).scale(0.5),
B.animate.move_to(b).scale(0.5),
A.animate.move_to(a).scale(0.5),
lag_ratio=0.5
)
)
tri = VGroup(C, B, A)

tiny_triangles = sorted(tri.family_members_with_points(), key=lambda mob: mob.fill_color.get_hex())
self.play(VGroup(*tiny_triangles).animate(lag_ratio=0.25).set_opacity(0), run_time=3)
self.wait(0.5)
```

uses a large amount of memory. It's worth investigating how exactly this memory is used, and how it can be reduced.

## Expected behavior

## How to reproduce the issue

Code for reproducing the problem

```py
Paste your code here.
```

## Additional media files

Images/GIFs

## Logs
Terminal output

```
PASTE HERE OR PROVIDE LINK TO https://pastebin.com/ OR SIMILAR
```

## System specifications

System Details

- OS (with version, e.g., Windows 10 v2004 or macOS 10.15 (Catalina)):
- RAM:
- Python version (`python/py/python3 --version`):
- Installed modules (provide output from `pip list`):
```
PASTE HERE
```

LaTeX details

+ LaTeX distribution (e.g. TeX Live 2020):
+ Installed LaTeX packages:

FFMPEG

Output of `ffmpeg -version`:

```
PASTE HERE
```

## Additional comments

Run the provided `Frac.construct` scene and profile memory through the repeated `AnimationGroup`, copying, and final opacity animation. Trace where memory grows and compare it with the scene's progressively nested `VGroup`; done means identifying the source of the large usage and reducing it without changing the demonstrated animation behavior.

Written by the indexing model from the issue text.