Many lay folk (non-techies like your aunt or next door neighbor) complain their PC is too old and slow, but often times what's really going on is that websites are running scripts that make dozens of synchronous calls that wait for a response back before the page can finish loading. Simply blocking that junk can be just as good as a new PC or a fresh install of Windows. Personally, I don't mind advertisements; I just don't like it when the digital marketing creeps follow me around or get in my way.

In addition to browsing in private mode, another option is a browser plugin called Disconnect that blocks (and visualizes) 3rd party tracking URLs. It will also improve the responsiveness of websites.
https://disconnect.me/