Any of the major distributions focused on simplicity and routing that also receive regular security updates should meet your needs.
A Google Wifi setup (with it's automatic updates) is probably better for privacy and security than the TP-Link. Better still would be pfsense, vyatta. Personally, I use an ER-X running a minor vyatta fork and it's rock solid.
>Who cares about Spectre and Meltdown in a game console or set top box?
The business model of consoles is subsidized hardware, with the bulk of revenue coming from game licensing fees (per copy). These vulnerabilities would reduce the security of the consoles which would directly put that business model at risk (unlicensed games + piracy).
>Especially if the game console is airgapped because I'm playing a single-player game from a cartridge or optical disk.
Between 10% and 30% (depending on who you ask) exclusively play only online games. The number of mixed is harder to discern but significant. About 50 million people use xbox live, microsoft's paid online gaming service. Last year, over 80% of game sales were digital. The business and consumer landscape simply would not accept airgapping.
These consoles are often used for other entertainment and health applications. Many of them have cameras attached to them (I know, I know). They are tied into peoples' cloud accounts. They are used for web browsing. They are used to watch porn. People deserve privacy, I think we can all agree.
You, personally, may not be affected, but these are concerns that cannot be ignored, both by users and business.
A Google Wifi setup (with it's automatic updates) is probably better for privacy and security than the TP-Link. Better still would be pfsense, vyatta. Personally, I use an ER-X running a minor vyatta fork and it's rock solid.