Looking at voip specifically, you've got what's called a jitter buffer, which lets you collect late packets, either out of order or delayed, and still use them, but delay is bad for user experience, so you tend to make that buffer as small as you can. You don't retransmit voip packets, because if they're not fresh, they're not useful. LIFO doesn't make sense for voip, because either you run a very long jitter buffer and nobody wants to talk with you like that, or the delayed packets can't be used.

The tcp retransmit timer is used when you send a packet (or packets) and don't get any acknowledgements. But if you send many packets, and the peer misses one (because it's delayed/out of order), it will send an ack of the last in order sequence (and hopefully selective ack too, it's 2022). If you recieve enough acks of the same packet, that triggers fast retransmit; by rfc2001 and updates, three duplicate acks is the threshold to retransmit, without waiting for the retransmit timer. LIFO would significantly harm the network in case of bursty traffic: if my flow sends 5 packets back to back (which is common with tcp segmentation offloading), and they get queued, they'll get sent to the peer in the exact wrong order, and thaf peer will send the same ack for the first foud packets, before sending a new ack on the fifth. My side will get those first four acks, and retransmit the first packet of the burst, then get the fifth ack, and maybe release a new burst. That's an extra full packet, plus it's typical to only send every other ack normally, so that's extra acks on the return side. Dropping a packet in the flow would still result in extra acks though, but the retransmitted data packet wouldn't be a duplicate through that bottleneck, because the first one was dropped before the bottleneck.