Is BTS considered bigger than top actors, actresses or athletes in korea for general public there?

Easy. YES

We need to ask the Koreans

Yes

We are not Koreans OP.

I mean they made it to the top 10 for list of 'The most impactful people in korea' for two consecutive years which is dominated by politicians, social workers, etc.

Ask Koreans

im not Korean but i would say yes