As a constant Wireshark user who's personally thanked Gerald Combs for this tool, we don't need an alternative to wireshark, just some architectural refactors. Many packet dissection fields are embarrassingly parallel, but because some of them can involve previous/future packets, wireshark does all packet dissection in a single thread. So when I scoop up 10M packets it can take 20 minutes for the GUI to load them all with a single core, while 100 other cores on the same machine sit idle.

Once loaded, you have to be super careful. One update to the filter bar, like "!icmp" and you'll have to wait another 20 minutes for all the dissectors to be re-run (for some reason.)

As a previous commenter stated, if you work with Wireshark a lot, you eventually write your own tool for your performance needs. It feels magical to have a 3-page C program sitting over libpcap giving reports in miliseconds that would take wireshark minutes.