It is more of an issue as to how many shots you get, what BS, and what strength and AP or not, whether cover is on the table (forests, obstacles, screening units), and what the targets are. In 7th edition where there were a lot more small units where shooting could kill 25% and induce panic tests or cut down a unit or finish off the last remaining models, shooting had more value. But against certain armies in 8th edition, shooting can be very effective. Orcs and Goblins often play units of snotling pump wagons, mangler squigs, and chariots that can hit hard and cut through elite units. Unit of crossbows or handguns against such an army are entirely worthwhile. Also, one should not underestimate the value of shooting in slowly eroding the size of a horde unit to the point that one can finally deal with it once in combat.
Units that can move and shoot (march and shoot in the case of Empire archers and other skirmishers and fast cav), can be very effective.
When I play dark elves, I almost always have two units of repeater crossbowmen. They have better BS and two shots apiece from the first and second ranks and, with 24" range, usually get at least two turns of shooting and kill enough to earn more than half their points costs (which is wht one needs) and still can hold something up or act as diverters or even charge some skirmishers.
When I play Daemons, a unit of six flamers is always one of the best units on the table for the points cost. The ability to march and shoot with S4, flaming attacks, good BS, and D6 shots per flamer is huge. Plus they are skirmishers with decent toughness, a ward save and unbreakable.
Leadbelchers are another example of a great shooting unit.
The problem with handgunners and crossbowmen of empire and dwaf armies is that they are move or shoot troops with only average BS. That means that they have to be positioned correctly to anticipate the opponent's units that can be targetted and opponents can avoid being shot by deploying out of range, screening units, and moving out of forward arc for some or all in the units. Since you cannot move and shoot, you have no option of moving forward to get in range to shoot on turn one (especially with handgunners) in many battle scenarioes and cannot turn the unit (using swift stride) to shoot something threatening a flank (like skirmishing scouts and ambushers). That is one of the reasons why I was surprised they increased the point cost of hangunners and crossbowmen, yet they reduced the points costs of archers (which are skirmishers and can, therefore, march and shoot, are harder to hit, have unlimited free reforms, and can wheel as needed). For those reasons, I am favoring running archer detachments (including to hide an engineer in them) instead of handgunners and crossbowmen and using the Hellblaster volley gun (which can pivot to shoot) with an engineer in range as the main shooting option due to the number of shots and hits and strength 5 with AP it provides.