I have recently proven that kaguya' ETSO is greater than large planet. Read here[
[1]], and as I said earlier, she was still weak compared to her prime. The juubi was never at full power during the war, and still it's energy levels reflected that of a planet at the very start of its many attempts to gain more power. And its power and energy only grew as the war progressed. In fact, the juubi went through some transformations during the war and before each one the juubi needed to increase its level of power.
Feel free to fact check my words, I'm sure you'll find this all within the chapters of the war arc.
To recap:
•The juubi' energy levels were that of a small planet in a massively weakened state and at the very beginning of a long run to gain more power.
•The juubi then goes through 3-5(not exact) transformations, each one requiring a greater level of power and energy.
•The juubi begins stealing chakra and stamina from the shinobi alliance, even fully draining hundreds of kurama cloaks
•The juubi spawns a god tree which then captures not only the entire alliance, but the populace of the planet and drains their chakra and stamina.
•Kaguya' revival using madara, which required a massive surge in chakra, 'way stronger than the tentails', a direct quote which places weakened kaguya above the juubi.
•Then another surge of chakra used to stabilize the biju chakra inside the juubi.
All those increases in power plus kaguy' use of ETSO, which I have provided the link to that thread.
So not only is ETSO stronger than large planet, the juubi power was capable of this all while not being at 100%. And kaguya very obviously was handicapped her self as she stated throughout the war and while lusting after Sasuke and Naruto chakra which was actually her own. She too was weaker than her prime self and not at 100%. They only had fractions of their full power, so simply put large planet is lowball.
Their upgrades are long overdue.