Does page speed affect my Google ranking?

Yes - page speed is a confirmed Google ranking signal through Core Web Vitals, but it is a tie-breaker, not the main event. Relevance and quality of content come first:

• It decides close calls - when two pages are similarly useful, the faster, more stable one tends to win.
• It is measured on real visitors - Google uses your field data (CrUX), so a fast lab score with slow real-world performance does not help.
• It is also a conversion issue - slow pages lose sales and enquiries long before they cost you rankings, so the upside is bigger than search alone.

Chasing a perfect speed score on a thin page is wasted effort; speed amplifies good content, it does not replace it. Get the page genuinely useful first, then make it fast - both matter, in that order.