Google's John Mueller responded to a concern on Reddit about a site that scored a D with its Pingdom score. Pingdom measures sites uptime and overall page speed metrics. John Mueller responded to the concern saying, "this is not affecting your SEO."
The person on Reddit asked, "Is this an issue? Pingdom score 68, 2.22 Sec load time." Adding, "local services business, is this performance affecting my SEO, or should it not be a priority?"
John Mueller responded that this is not impacting the SEO of the site, he wrote, "this is not affecting your SEO."
Here is a screenshot of the D the site scored:
Now, Google does not use Pingdom metrics for ranking. It does, on a super tiny basis, use Core Web Vitals - but even then, they don't really move the SEO needle.
That being said, if your site is super slow, you probably want to make it faster for your users.
Forum discussion at Reddit.