There is a reason for businesses to spoof a number.
Let's say I own Bob's National Grocery chain. My internal number is 888-555-1555. When I dial out, for privacy reasons, my number shows as the internal switchboard number - 888-555-2627 ("bobs" lol). This should not be a problem, as (1) my company owns this number and (2) it is answered. The issues here are two fold:
1. How do you determine the number I am advertising is mine? The answer here is simple - for numbers I advertise out from my phone switch, I must own these from the phone company I am peering with (first hop) or have some way to prove that I own those DIDs if I have multiple peering companies. Not a difficult hurdle to overcome.
2. How do you determine the number I am advertising (assuming step #1 is valid) is a valid company or answered number? In the case of robocalls or spam, my company could prove I own a block - satisfying #1 above, but turn out to be a voicemail box that's full or a non-company-answered blank DID.
About 15 years ago, I played around with a company owned phone switch setup and found that ANY number I put to advertise outbound was picked up and relayed to the target's caller id. I made a few test calls to my cell phone to validate that this was possible and then promptly reverted back to the company's owned block.