Sites that are slowing down your computer might not be ads, it might be cryptojacking
If you’re surfing the internet on your computer or on your phone and suddenly everything gets really slow and your CPU usage starts maxing out, you may initially want to blame the heavy use of ads on a particular site. While that is a problem, a larger problem is cryptojacking-- where sites or even ads on sites can hijack your processing power while you’re on the site for mining cryptocurrencies.