At the same time, 10 Gbps on fiber is low power and great speed, but the form factor of SFP+ is simply too big for any laptop of 2022. In theory USB-C 3.2 @ 10Gbps to SFP+ fiber adapters are possible, but fiber is not popular outside server rooms, so there is no market for it.
As I said, never. It is not a matter of PCIe speeds, but a technology one: copper is power hungry and requires new cabling, fiber has no cabling.
So, there probably isn't a good reason for not putting it in a laptop. Like wifi, just speed shift it based on load, etc. AKA see 802.3az
So, the old max power draw models from 15 years ago, don't really apply entirely.
Mikrotik CRS305 ($150, 4x SFP+) & CRS309 ($250, 8x SFP+) w/ as many S+RJ10s as you want.
Mikrotik quotes 2.7W per transceiver at 10GBASE-T.
https://www.servethehome.com/mikrotik-crs309-1g-8sin-review-...
https://mikrotik.com/product/s_rj10
So yes, it's a bit hot, but definitely something you can get done well under $500 if you want copper.
~$120 per port (assuming 309s, the recommended interleaved spacing, and amortizing the switch cost over # ports) isn't very expensive if (a) you need the capability & (b) already have copper in the walls.
Drywall finishing along will run you that much. :) But yeah, new builds should definitely be fiber.
How often do you have your laptop plugged into networking but not power? And if that's an important use, I could see manufacturers spicing it up with some power over ethernet to not only fix but reverse the problem.
Though it feels like ethernet ports on laptops are already unsexy at any speed. And you could have the 'balanced' power profile limit the port to 1Gbps on battery.
A 25 foot cable on monoprice costs $6.49 for cat5e and $7.99 for cat6. It doesn't matter at all.
I could get cat8 for $22.49! Compared to what you're plugging that into for 25/40Gbps that's nothing.
The last batch of cables I bought was 5x 10 foot cat7, for $22 total. (You're not 'supposed' to put normal plugs on cat7 but nobody really cares.)