I'm looking for some advice on switching domains for my survey/giveaway website.

I purchased a website that gets around 1,500 in traffic and makes a few hundred in Adsense. The previous owner had rebranded the site and changed the domain which ended up hurting his SEO and traffic. Before, when it was running well on the old domain, it made 1000-2000 on Adsense.

It's been a few years since the rebrand but the original domain still holds a lot of authority and got way more traffic. Should I consider switching the website back to the original domain to try to improve rankings again or should I just focus on the new domain?

The website now is snipon.com and the previous domain name was surveyh.com I'm wondering if switching back to the original domain will still be beneficial or if it will just mess up what's happening now on the rebranded site.