Sounds like you are de-essing , which can be done using the upper band of a multi-band compressor, or via a de-essing plug-in like Spitfish or LISP.
2800Hz is unusually low for de-essing, (i.e. may remove too much high-frequency causing dull muddy result).
In my experience the lowest threshold is 4KHz , and typically 6-8KHz.
It depends on the performer/mic/ etc, we’d have to hear a short unprocessed sample which included sibilance to be more specific.
IMO the main problems are …
a hint of overload distortion (mic a bit too close to mouth)
the occasional click, (e.g. on “T” of “the basis”).
Noise level could be reduced a bit.
There isn’t excessive sibilance on your sample, quite the reverse : a big notch in the spectrum at 5KHz has reduced the high frequency content. De-essers only apply notches like that momentarily when sibilance gets above a threshold, whereas applying such a notch with an equalizer removes high frequency from the entire track, which can make everything apart from sibilance sound muddy.