Why is PSL more popular than IPL?

Yes, PSL is more popular than IPL.

Do you know why?

During PSL 2018 (22 February – 25 March 2018) –

India, Sri Lanka & Bangladesh were playing Nidahas trophy.
Australia was playing with South Africa.
England was playing with New Zealand.
Afghanistan, Ireland, Scotland, UAE, West Indies & Zimbabwe were playing Cricket World Cup Qualifier.
During IPL 2018 –

There is not a single bilateral series being played