I suspect the improvements are even more dramatic going from Zen 1 through to Zen 5. AMD has really hit the jackpot with how scalable the Ryzen CPU is considering how they're able to improve the performance from year to year. This is a stark difference to the FX series during the 2010s, which saw very small YoY performance increases by comparison. Ryzen really is AMD's equivalent to what Nehalem/Core was for Intel back in the mid 2000s.
That is all true but I will defend the FX series a little. Mostly now that there is a lot of software that scales across cores better now, they haven't aged as terribly as others have. They aren't great but not terrible considering.