My opinion on the matter:
The gold niche has been a well-established one for dozens of years. It is not like, for instance, other forumers mentioned AI, electric vehicles, etc., which will drive a lot of new players in the industry.
The only way I see an influx of businesses interested in domains would be if the fiat currencies would go into hyperinflation and people would heavily look to purchase more gold.
The buyers for gold domains are mainly companies that look for shorter, more brandable domains.
You may consider doing outreach to those who may be interested. If you get a positive response, sell it or keep it. If not, drop it and don't look back. At least, that's what I would do.