I think stagnation is a fitting description. Gigabit came out in the 1990s. It is still the mainstream speed. For example, a base mac mini, despite being one of the fastest machines you can buy, has a gigabit port or optional $100 10-gig port. There is no option for a 2.5 gigabit port. An iMac comes either without ethernet, or with gigabit. NUCs come with 2.5g, I grant you that, and I attribute that to Intel's push for the standard. But their 2.5g chipset notoriously doesn't work.

2.5g is on the higher end of devices a consumer would buy today, and lacks support among even slightly older devices. Wifi 7 is similar: it exists, but just barely. There is a Wifi 7 device in my hand right now, but few people own one. Under ideal conditions WiFi 7 whoops 2.5gbps ethernet, though. Even 6E which came out years ago, gives comparable throughput to 2.5g ethernet.