When is it too "old" to play in a high level.


Mikhail Chigorin hadn't started playing chess seriously before the age of 24. And he became a WC contender playing two matches for the crown and coming close to becoming a world champion. Of course, chess was nowhere near as competitive as now, but it does give you an example of someone becoming very very good even though starting late in life.

Paul Morphy started playing chess at the age of 19. He was doing it just to kill time because he couldn't legally practice law till the age of 21 in the state of Louisiana.

on the other end of the spectrum, Victor Kroichnoi was still banging out speed chess with other GMs in his early 90s.

STOP ASKING QUESTIONS LIKE THIS ON THIS WEBSITE AND STOP ALLOWING OTHER PEOPLE TO LIMIT YOU AND STOP LIMITING YOURSELF AND STOP LISTENING TO OTHER PEOPLE.

STOP ASKING QUESTIONS LIKE THIS ON THIS WEBSITE AND STOP ALLOWING OTHER PEOPLE TO LIMIT YOU AND STOP LIMITING YOURSELF AND STOP LISTENING TO OTHER PEOPLE.
Stop spamming caps and making your words big
when you’re 6 feet under
Cremation may help. Or an undertaker with poor measuring skills.
STOP *snip*
Stop spamming caps and making your words big
But nobody listens to him otherwise. He started too late

It's a little depressing that we have to go back more than 115 years, well before the title of Grandmaster technically existed, to find someone (Mikhail Chigorin) who started playing seriously after the age of 20 and made it to Grandmaster-equivalent.
Paul Morphy started playing chess at the age of 19. He was doing it just to kill time because he couldn't legally practice law till the age of 21 in the state of Louisiana.
This is not true at all.
Morphy started crushing people already as a child and learnt chess from his father and uncle when he was still very young.
He went to Europe to play the best players in the world when he was something like 19 and could not practice law yet, but that is not when he started playing chess. At that point he was already considered the strongest player in the US.

My two cents would be that "playing seriously" is subjective, and even if the goal were concrete, no one can tell the future, everyone responding to you would just be guessing. To describe the nature of the challenge though, the artist Drake raps the lyrics, "They don't know they got to be faster than me to get to me... No one's done it successfully." You can absolutely play seriously, no matter what that means to you, but to reach that goal, you have to be willing and able to train not just as hard, but harder, than everyone else that shares that goal.