Blurry vis_miss in pdf output

[garthtarr]

When I export a vis_miss to pdf the edges of the cells are blurry...

---
title: "Untitled"
format: pdf
---

```{r}
visdat::vis_miss(airquality)
```

On the left, in the RStudio interface, it's the expected behaviour (fine when exporting to png), but on the right where it's exported to a pdf, it has the smeared effect... I don't know why that is!