I’ve heard that theory before … the thinking being that a long registered site will flag to google that it’s not a fly-by-night site.
It’s a lot of speculation and once you’re above 1 year renewals I don’t think it gives much of an edge at all (if any).
Google does seem to favour sites that have already done their time – so a domain with 10 years age already has a big advantage over a 3yo sites, which in turn is much better than a 1yo site.