It's up to the merchant to decide if they want to support offline payments and to what limit. The terminals certainly allow it. Your transaction will be stored in a secure way (either encrypted or in a secure element) until the terminal reconnects.
The way the rules are set up though, the risk of a failed offline transaction is almost entirely borne by the merchant. In most cases the merchant is unwilling to accept this risk and disables the feature.
I guess for a restaurant it basically always makes sense to accept offline payments. I wasn’t aware that they might not be able to process card payments when I ordered.
I don’t typically carry any cash on me, and, well, if their terminals go down before I’ve closed my tab, they assume all of the risk anyway.
I think it’s still pretty frequent even nowadays. I have payment cards with systematic authorization and and others without and I can totally see the difference.
Transactions with the cards requiring authorization will take several seconds while with my other cards it will be instant most of the time.
It depends on the configuration of the terminal : most merchant will allow offline (or asynchronous) transactions up to a certain amount when there is an important flux of customers waiting to pay.
I’m also pretty sure (that’s speculation at that point but I felt it in my experience) that some cards have more chances to have instant (offline) transactions than others. The more « premium » the cards the less I saw the "waiting for authorization" screen. Especially for small amounts.
About 15 years ago I remember paying for fast food delivery where the delivery guy put your card under the carbon paper bill and just rubbed a pen sideways back and forth over it a few times
It also depends on the card. The card can decide and even stores a running counter of how much has been processed offline, after which it will want to go online to check and reset its counter.
The way the rules are set up though, the risk of a failed offline transaction is almost entirely borne by the merchant. In most cases the merchant is unwilling to accept this risk and disables the feature.