[stblack]

In my experience, the size of the hosts file matters on some devices, and some os.

On older versions of Windows, for example, networking and browsing slows noticeably as the size of the host file increases.

The same can be said for rootable mobile devices, though it’s less noticeable off WiFi because cellular latency is so much higher.

I would guess, marginal consumer and home routers will suffer with larger hosts files, but I don’t have sufficient experience to claim this for certain.

Background: years of discussions and issues at https://github.com/StevenBlack/hosts, which I maintain.