Your framerate is capped at 60fps, which means that the average can only be lower than that.
Based on the 58fps average, I would expect this to be totally playable.
The occasional dip as low as 48fps probably isn’t great, but could be a heck of a lot worse.
If you’re CPU bound, consider increasing the resolution scaling to shift more work to the GPU.
While your CPU is probably a bottleneck for that GPU, as long as you get a playable experience that’s not really as big of an issue as the internet would make you think. You’re leaving performance on the table. Reframe: you’re saving some performance headroom so that when you do inevitably upgrade to a newer CPU, that upgrade will feel even more impactful.