All Capital Gain/Loss is reported on Form 8949, so that form goes with every return, whether you Efile or mail.
The difference is that if you choose to Enter Summary Info (one line for LT, one for ST, etc.) that is what appears on Form 8949. In that case, you mail your Form 8949 (which is still included in your return if you Efile), along with the detail for your summarized transactions. That detail could be a 1099-B, a CSV file of crypto transactions, a PDF of a consolidated 1099, etc.)
So it's not a TurboTax issue; it depends on how you want to report your transactions. If you imported your complete broker info, for instance, you will not have to mail anything. You are correct that certain types of transactions don't require details to be sent separately.
Here's more info on How to Enter a Summary in Lieu of Individual Transactions and Mailing Form 8949 for Summary Totals.
@Tom in Carolina
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