FWIW, I just had an issue with my host about this. They 403/disabled my site briefly today because of heavy traffic, and told me they had been having issues with traffic load. That was surprising to me (I'm not that popular, grin). Here's what we finally figured out:
From my hosting co. customer support:
"Note that we have noted your site causing server load issues on many occasions as a result of your WordPress installation which has a history of not scaling well when heavy traffic hits it.
"One theory is the Achive links that WordPress adds to your header, if you view the source of your index file you will see a large number of lines of code starting with:
"When we see loading issues with your site many times there are a large number of hits for proxy server IPs and the theory is that these proxies are cacheing your site and hitting all of those archive links. Many of the IPs we see when your site is causing loading issues are corporate, educational and Gov't/Military proxy IPs which appear to prefetch content when someone accesses a site.
We would recommend removing those archive links and investigating modifying WordPress to not add those back (or additional as time goes on)."
I checked the source and they were right -- 7 years of monthly archive links being fetched....
I removed wp_get_archives from the header and it all seems fine now. But thought it might be of interest to others in this community.