Somehow I don’t think ability score increases in D&D 5e are the cornerstone holding the notion of nimble elf archers together.
There is such a strategy: if it’s important to you, then give your elves high Dex. Problem solved.
Or...do you mean it’s important to you that other people also give their elves high Dex? If so, maybe you should think about that.
I agree, the nimble elf archers are a trope that is over a 1000 years old. It has much going for it.
Still, when oppression is no longer the viable strategy, one is forced to think about a reason to exist (raison detre). Does Dex really matter?
Why do elves have Dex? How does Dex adapt? How does Dex ensure survival? How does the culture reward Dex? Why is a magical population physically dexterous? Etcetera. In what ways does Dexterity matter?
Going by British folklore, the elves are a blend of Norse alf, Celtic sidhe, and French faie. The result is a new creature. This is a land nature spirit, resonating fertility of the soil and animals, and fate. These elves rewarded good and industrious humans, but punished evil or lazy humans. By Shakespearean times, the punishments were mostly pranks. European Christianity only allowed for good spirits versus evil spirits, and never knew what to do with nature spirits that were neither. Christianity tended to demonize nature spirits, more often than not, but there continued to be resistance because the culture felt strongly that these nature spirits were not really evil, even when they admitted they werent really good either. The culture of Shakespeare offered the solution that these spirits were childlike, and innocent and playful, but hadnt yet developed an adult sense of morality, and could punish people who were not nice by playing pranks. The pranks included elf-shot, that were invisible spiritual arrows. The results of these arrows ranged from mysterious muscle spams, and sudden pains and cramps, to ones leg falling asleep and starting to tingle painfully, to epileptic seizures and deadly strokes.
Tolkien tended to translate these nature spirits into humanlike ethnic groups. The elven humans seem to maintain the affinity with archery, and generally keep their (childlike) innocence. But his elves were once powerful because of magic but now are fragile and frail, with the prevalence of nonmagical humans.
D&D cohered with Tolkien elves, being mundane, while gaining Dex for bow, and a Con penalty for being frail.
In my eyes, a defacto human ethnic group who simply likes bows and Dexterity, is not really an interesting concept worth preserving. Players who do enjoy this kind of elf concept, might want to develop the concept further.
I enjoy more the skyey angelic luminous solar elf, that are inherently magic even made out of magic, as a concept. This population has little or nothing to do with Dexterity (or bows). I think about the tropes of beauty and art, and how Charisma matters to their culture of magic. Their leaders and spiritual leaders are moreso Bards. Lore Bards are prestigious. Intelligence also matters. Their academics and magic item makers are moreso Wizards.