More sensitive and selective receivers are needed , for that extra sensitivity and selectivity in reception when one is into SSB and CW receiving or actual QSOs, as most of the ham radio stations are using 100W or less on their wire dipoles and GP antennas.
But then in this case, it would be better getting the HF transceivers rather than receivers?
Sensitivity does not help you when the system is either external noise or interference limited.
Selectivity does help in some extent, if it does suppress strong interfering signals at larger spacings from the centre frequency, but not if the causes of interference come from adjacent channel emissions from the transmitters falling into the wanted signal passband of the receiver.
"Yesteryear", when the arms race between the HF broadcasters was in full vogue, the large-signal properties of receivers were crucial, as the vast amounts of strong signals around especially in Europe created intermodulation noise and other overload effects.
The only remedy was to add RF selectivity in front of the receivers so fewer signals reached the front-ends, and to adapt the input level range to the antenna noise factor so the receivers were not more sensitive than necessary.
This was the "credo" of the "receiver guru" at Marconi, B M Sosin, during the 70s. Some other informed people, like G3PDM, DJ2LR, W7ZOI and W0IYH, also "jumped on the band-wagon". Most others continued to focus on sensitivity.
Today, the focus in amateur radio still is on receiver performance, and there are receivers that claim sub-microvolt sensitivities and 110 dB close spaced dynamic ranges.
Seen in perspective, the common HF user today has an antenna noise figure of 30 to 40 dB on frequencies below 10 MHz, corresponding to an usable sensitivity of around 2-2.5 microvolts.
It takes specially selected and protected receiver sites, far away from man-made interfererers, to get lower.
Further, a receiver adjacent channel suppression of 100 or 110 dB is quite useless when the suppression in typical fielded transmitters is perhaps 40 or 50 dB worse.
Professionals realise this, and adapt the frequency allocation plans for e.g. military and aeronautical HF systems to the expected equipment performance, both receivers and transmitters.
Very few users, amateur or professionals, are going to notice any greater difference today if a "mediocre" receiver is substituted for a "premium".