I don't think that's quite true. Unifi 10GbE switches are cheap enough I have a 24 port PoE+++ one in my house and my 3 main WiFi APs are 10GbE connected. My MBP uses a 5Gbps Thunderbolt adapter that runs relatively cool as well. All of this is over the existing Cat5e wiring.

I'd say 10GbE has arrived. It is relatively cheap, most of the time works over existing 1GbE cabling, and gracefully degrades to 5/2.5/1Gb based on conditions when it can't reach 10Gb.

Yes to be 100% guaranteed of getting 10Gb even in bundles of 100 cables running over noisy fluorescent ballasts to a full 100m you need Cat6A but in many environments Cat5e or Cat6 is more than sufficient. It works so well if you fail to get the full 10Gb I humbly suggest you re-do the terminations on both ends before considering replacing the cable.