Whats the point of excavation levels/experience? (Spectrobes 1 for DS)

Hello,

after scouring multiple wikis and walkthroughs I seem to miss the purpose excavation levels have entirely - is anyone feeling the same?

The best and most detailed walkthrough, probs at that writer btw, only tells me that the levels are extremely grindy and have only 2 advantages:

1. Faster excavation with tools

2. Less damage to the stuff we excavate

But here is the thing:

1. is made void by the giga tool, which just gives me the mineral instantly thus reducing the time I need to spend excavating drastically. The giga tool is available as soon as you get to the shops in early game.
2. is also completely meaningless since, if I want that fossil with that special part and/or high starting energy, which is not much to begin with anyways - I just go slow.

Sure - I will get less or no experience points but then again, if those are the only upgrades, who cares?

So... does the excavation level do anything beyond those 2 points that are completely meaningless essentially?

Thanks for your help!

Best walkthrough I so far found:

https://gamefaqs.gamespot.com/ds/932841-spectrobes/faqs/47770