I wouldn't put too much stock in something like that. With things like cancer, war, AIDS, COVID, starvation, murder and rape... sports are but a tiny spec on the radar. So your parent's country has bad athletes (I don't know whether they do or don't; I'm just taking your word for it)? Okay. So what? Does it really matter in the end? Are you still going to wake up tomorrow, eat the same-ish food that you always eat, do the same-ish things that you always do and then go to bed at night? Yes?

Then stop sweating it!

Emancipate and give yourself up for adoption

It might depend a bit on the sport. Luxembourg where I live sucks at most sports, we only send 11 athletes to these year's olympics with no hope of winning a medal (the last and only time we did was almost 70 years ago).

At the same time we won the Tour de France 5 times with 4 different riders and are record world champions in 9-pin bowling.

I feel this is far less important than you make it sound like.
There are no ranked tennis players from my country yet that never crossed my mind as a negative/problem. Im not serbian yet I was rooting for Nole throughout Wimbledon.

Then become good at sports and make your country proud!

To answer your question, Bangladesh. Already had 60 million people in the 70s, no Olympic medals to this day.

Not sure if Honduras has a basketball team but if they do there has never been a better time for other teams to beat team USA. They kind of suck so far in exhibition games.

I still remember David Suazo

My country sucks at football. It’s a national trauma.

Worst thing is: we used to be good, but now we suck and keep on sucking.