The shortwave frequencies still feel very underutilized. When I scan the FM (88 - 108 MHz) and AM (540-1600 kHz) radio frequencies, I pick up a lot of stuff. The shortwave band is relatively vast and feels very sparse. Considering how valuable spectrum is these days, it's hard to believe that we couldn't find a better use for it. Is it because it is so prone to noise that it's less valuable?
In amateur bands, symbol rate below 28 MHz is limited to 300 baud.
It's really frustrating if you want to do any development with digital modes.
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Looked it up, it's a 19.6k symbol rate limit(rather than leave it open and restrict bandwidth). You can carry a ton of data on 2M if you wanted but legally you can't exceed the speed of an old dial up modem.
Here in LA (Norway, for the ham prefix challenged), we can modulate in whatever way we feel like on 2M, as long as the signal bandwidth does not exceed 18kHz.
(So, using a clever modulation scheme, you could get very close to the Shannon limit for the given channel bandwidth and noise level - assuming a very healthy 30dB S/N, one should be able to wring approx. 180kbps from an 18kHz channel. (Granted, in the real world with filters without infinitely steep skirts we'd get nowhere near this - but, let's say you could get 1/3 or so without trying too hard.)
There are bandwidth restrictions on the 60m band, where amateur radio is secondary.
I love amateur radio but at least on the 2m bands it's mostly dominated by people just chatting on repeaters with others they already know or dead quiet. I monitor 146.52(our calling frequence) on my ~300mi weekly trip and I've made only one contact in 2 years.
APRS is pretty dead, there's a ton of interesting stuff that could be done on the ECC and symbol rate front but no one really seems interested. Not much has changed on the spec for a long time. Compared to some other countries where they have some very robust and flourishing 2m digital modes it's a shame.
But as others have said, in many parts of the world there aren't many shortwave stations left. Africa and parts of Asia still have quite a few however.
You can think of the trade off roughly as "frequency increases increase bandwidth and decrease penetration/range"