Ripple’s performance has been better as it is not only faster but also the cheaper one and can scale much more efficiently than Ethereum. And yes, in September 2018 it was on second position, but it didn't last long. Ethereum quickly regain its leading position. Wll it repeat? Depends on future development of ethereum, whether it will be upgraded to ethereum 2.0. or not. Because now both speed and cost of transactions of ethereum are disappointing.