Disclaimer: I am not a lawyer. I am not a CPA. Consult one for yourself.
If you deposit 10k from your bank on Coinbase, convert to USDC for free, test it by sending it to your friends, get the 10k USDC back and sell it back, and put it in your bank account... is there any profit or loss? If not, why would it need to be reported to the IRS?
If you buy 50k of gold bars, the price goes up, sell them for $60k, that's 10k of profit that needs to be reported to the IRS.
Same thing for virtual currencies. If you make a profit or loss, it needs to be reported.
In my 10k USDC example, it's possible that the IRS could look and only notice the withdraw from Coinbase to your bank. They may ask "where did this 10k come from?" Then you can show them the prior deposit of 10k from your bank to Coinbase, that evens it out.
Then they look at you like you're crazy and say "so you just sent 10k to your friends, they sent it around to each other. Then back to you, and then you just put it back in your bank account?"
And you, excited—your left eye twitches, reply "Yeah! Isn't that great?"
Then they give you this look the whole time you're explaining everything.
So yeah, keeping a few records is good. Coinbase is also very good at keeping deposit and withdraw records too. They can even download spreadsheets with custom dates and everything to help you with reporting if it becomes necessary.
Buy I honestly don't think anyone working strictly in USDC will need to report anything, in much the same way as anyone reports PayPal transactions. Again, I am not a CPA or a lawyer... this is not official advice, consult one for yourself, etc.