That is no longer true - on several sites (eg. Ars Technica), ads are loaded and refreshed after a short period. Auto-refresh ads still do most of the work on

That is no longer true - on several sites (eg. Ars Technica), ads are loaded and refreshed after a short period. Auto-refresh ads still do most of the work on the ad servers and very small amount of resources are eaten on the user side in the browser. This too is done with a predefined logic which are user-action based or event-based. Time-based auto-refresh ads are only seen on bigger sites which usually have very high average session times. So regular news and clickbaity sites won't necessarily have those. Auto-refresh ads are only served by bigger ad networks which server bigger sites, Google Adsense do not allow auto-refresh ads. Google Ad Exchange does but that network is for bigger sites. This weeds out all the potential scammy/spammy sites which go for exploiting user resources like cryptominers do.