We have a customer who recently migrated from Wix to our headless CMS offering (which is WP/Next.js based) and their organic search traffic has improved 30% over the course of a month. But we believe this was largely due to CWV/speed improvements; impossible to parse out how much was due to Wix’s JS-based architecture itself.

Wouldn't want to presume without seeing any data and barely using Wix, but I wouldn't say Wix is known as a ranking hero platform lol.