Last I checked there were about 4-10 TTF bugs discovered and actively exploited per year. I think I heard those stats in 2018 or so. This has been a well known and very commonly exploited attack vector for at least 20 years.
Having said that, the "arbitrary code" found in TrueType is not really arbitrary either - it's not supposed to be able to do anything except change the appearance of the font. From a security standpoint, there's no theoretical difference between a WAV and a TTF font - neither can hurt your machine if the loader is bug-free. Practically speaking though, a font renderer that needs to implement a sort of virtual machine is more complex, and therefore more likely to have exploitable bugs, than a WAV renderer that simply needs to swap a few bytes around and shove them at a DAC.