So, (assuming on mobile) you have selected to delete browser data on Firefox (fennec). Because of that and because there is no setting to white list the sites you'd like to keep cached, those sites load more slowly. You could try removing the one for cookies specifically and then manually erase them on a weekly basis but that's more finicky. It may be better to use something like ublock origin to block cookies. You may be able to just whitelist the sites you want from there. Or switch browsers I suppose.