As a few others, “it depends”.
What’s your riding style?
Bimble in the saddle on the up and flat, boulder down?
Or
Attack everywhere out of the saddle, prefer not riding in the saddle, though you need a perch when you get tired or it’s boring?
Or somewhere between?
I don’t feel the need on my hardtail, i’m strong enough to put the saddle down and leave it there, for good lengths of time. However on my 6″ bike, it’s harder work, the saddle gets used more, but there are still obstacles that spring out at me on the flat and up that i still want to attack, i love having a dropper on this bike. It’s never clear for me, saddle for the ups, down for the downs, it’s all over the place in between.