I already said I think Ego's more powerful than Stormbreaker Thor a page ago (the last time you called me biased).
Ego wins 8/10
- On his home turf he can bury enemies under mountain ranges
- With Quill as a battery to double his power he was on course to conquer every planet in the universe at once via long distance matter manipulation.
- On his own he's powerful enough to send an avatar halfway across the galaxy and causally blow up an entire spaceship fleet.
If this was Thor vs one of Ego's avatars Thor would win but Thor vs the entire planet and endless avatars is a different story.
Thor doesn't know that Ego's core is a massive achilles heel and chances are Ego can wear Thor down and bury him before he figures it out/reaches it.