Got it. you can buy 2 switches, each switch has 8x 2.5G and 2x 10G SFP+ ports.@gocoax
The 16-port gig switch was $70 (years ago), and I used 12 ports.
The QNAP I mentioned is a rackmount 10-port managed switch, which Amazon has significantly more expensive, than other retailers. Possibly hoping to exploit consumers like me, that suddenly have new routers and want to utilize the network speeds (i.e Amazon just listed the GT-AXE16000).
That is maybe the best choice.