> There's 30$ usb-c adapters out now. Where-as 10Gbe is usually $130+.
Sure, but if you include another SFP+ port, you can run that at 1, 2.5, 5, or 10gbit. Another SFP+ port gives you a BUNCH of options (including the "copper, fiber, or twinax?" option). A 5Gbit copper port locks you in to just that one configuration.
As for the expense of SFP+ modules, go check out the 10Gtek company. The optical ones are very inexpensive [0], and I've had eight of their optical SFP+ modules in my home networking hardware for many, many years with no problems whatsoever. I expect the copper ones to be just as reliable.
[0] And their copper ones are on the low side of average price
5GBASE-T can run on Cat5e/Cat6 cabling which people probably already have. This makes the router a viable product, which can improve your home network performance with minimal investment, just by swapping out your old router.
OTOH, the dual SFP+ configuration is more on the exotic side. It may make sense on some professional setting (or some outlier home network configurations - like yours), but I guess this is not the intended market.
The operator of the device. Who were you thinking of?
> 5GBASE-T can run on Cat5e/Cat6 cabling which people probably already have.
There are SFP and SFP+ modules that will do 1, 2.5, 5, and 10GBASE-T just fine. If the operator wants to run 1GBASE-T, they can. If the operator wants to run 10GBASE-[SL]R, they can do that, too. Options.
> The dual SFP+ configuration is more on the exotic side.
1) Used to be that having a gigabit Ethernet port was on the exotic side, too. (If we go far enough back, 10mbit was hella fancy.) Times change.
2) Here are two SFP+ ports for ~140 USD. [0] Here are four for 150USD. [1] Times change, man.
Yes there are very few switches with 5Gbe. But I'd be open to that changing!