You need norms, and it isn't as simple as obtaining a certain performance rating, participants need to come from different countries too. Even if you have the skill all that travel time would get too expensive.
GM title without beating a GM?
You need norms, and it isn't as simple as obtaining a certain performance rating, participants need to come from different countries too.
That's the main way to earn a GM title, but not the only way. You get a GM title if you
- Reach the final 16 in the World Cup
- Win the World Over 65, World Over 50, or World Under 20
- Win a Continental Individual
It is extremely unlikely, but possible, that someone could get to one of those and win without beating a GM along the way.
This may not be in the spirit of the question, but Nona Gaprindashvili may have. She was the first woman to be a grandmaster, as she was given the title for being women's world champion, but I don't think she was ever legitimately grandmaster strength. The top women in those days didn't play much against men, and there were few grandmasters compared to today, so she may not have played many grandmasters.
Edit: I looked it up, and apparently she got the GM title in 1978, but won Lone Pine 1977. She must have beaten some grandmasters to do that, so no.
Has anyone ever achieved GM without beating a GM? I know it's possible in theory, but wasn't sure if it's practically possible. Seems like achieving a 2600 tournament rating would be very hard without beating one or more GMs.