Take my playstyle preference of separating roleplay portrayal from ability stats.
Take a player who has seen the movie with smart charismatic bare knuckle boxing Robert Downey Junior Sherlock Holmes. That player thinks RDJ punching Sherlock Holmes sounds like a fun D&D concept so they go monk for punching. Monk is MAD for pretty much everything but int and charisma. They do the stats for a regular monk and the low stats end up being int and charisma.
The PC takes a custom background as an investigator so they get the skill narratively and proficiency bonus mechanically when rolls come up but they are still not great at investigation rolls at low levels.
They roleplay being a charismatic investigator monk looking for clues, making deductions, going for witty quips on the player roleplay/non-mechanics end and effectively punching out bad guys as a member of a D&D party. The roleplay of a smart charismatic investigator is how they approach playing their character as a role.
Two views on this.
1 sounds like fun, cool.
2 That is cheating/bad roleplay, should have played an int class for that roleplay concept or been a monk with lower than normal monk stats to bump up the roleplay stats.