There is lots of activity on the 630m band:
http://njdtechnologies.net/category/630-meters/
and,conditions permitting,they are working some
very decent DX too most nights.
The FCC is supposedly giving much needed attention
to finally opening the band here.Meanwhile it's a ham
band in all but name with U.S. stations calling CQ and
the other things but using Part 5 Experimental calls.
(They can work foreign amateur stations.)
Why do they do it?
Because it's there and this (LF) is after all where it all began.
As for the other bands,propagation has been lousy.
6 meters is centered around 50.110 or so,the ssb dx
frequency...2 meters has been unfortunately ceded to
the Whacker crowd in many places...and after listening
to a few HF voice QSO's it's easy to see why CW is still
popular.
As for 2200m (136 khz) believe they are still kept at one
watt or so (may be wrong)...heard one in the 80's and
sent a QSL with congrats but he apparently was out
of stamps😊.