Characters in 5e are usually well trained at level 1, this is their peak before going on an adventure and honing themselves through that. So an elf or halfling could definitely get the training necessary to raise their strength up to 16 or 17 by the time they reach level 1 Adventurer status, all depending on their backstory and genetics. An Orc Wizard with 14+ INT (cause pre-tasha's your maximum is 13 I think if you pick normal Orc? (Not talking Half-Orc in this example)) could be statistically a rarity but a player might play that because the Orc in question was raised by non-orcs who were scholars and therefor spent his life reading and studying and not training up his martial prowess. His story could depend on the fact that he is not a musclehead and has mixed feelings about the Orcish culture he did not experience and a weird sense of lack of belonging to either. It is all character specific and the Optional rule enables people to play against typing mechanically and roleplaying wise, and doesn't lock anyone away from options, and it doesn't force itself on any player either.
