I think it depends on needs.
You may have enough and then decide you want to go on a special vacation which might include diving, caving, other activities.
Then you find your available flashlights do not cover these needs.
Or you decide you want to take up (or return to) biking. Well that's a whole new world of flashlight needs there.
Or you may decide you want to use red colored LEDs in certain nights or activities (eg., star watching).
Or you remember you still do not have a good UV flashlight (or infra-red, or laser). Or a big throwing light.
Or you may just look at what is available out there today and find amazing things you had no idea existed. This happened to me when looking through the 2021 Fenix catalog, link provided in the Fenix sub-forum.
I already had a Fenix headlamp, the HM23. This is amazing and served me well during a trip to Africa.
But I was completely floored by what is now available, and already think I like several others.
I also own several Malkoffs, in several different hosts (Five Mega, Oveready, Surefire, Malkoff's own MD line of hosts, the list goes on and on, even a Maglite).
Yet I see the new 18650 Wildcat and want it, too, in neutral.
So it goes. Between technology, clever and creative flashlight makers, and ever changing needs, there is never "enough." It is possible to find some kind of balance, but it will still be the case of getting rid of some and replacing them with others.
PS -- And I forgot to mention the batteries. The 18650 used to be rare, then it caught on, and then it became a flood. And what about the 26650? If you find a good light for it (I found the Emisar D4) you may add that to the collection. Now the 21700 is coming out, which for a long time was simply not available. It may make possible different host-drop-in combinations. Are you really going to stick with the AA's when you can get amazing runtime and lumens with a 21700 in a not-too-big host?
PS2 -- And I also forgot to mention the solar powered flashlights that can be used to recharge your smart-phone. They may now be good enough to consider. Shouldn't every bug-out kit have one of those in it?
PS3 -- And another thing, you can find Fenix headlamp with a 21700 battery! Now if they make one that can also charge the smartphone...