is it hard to get a bid from pi phi or theta?

what do you mean is it hard? those are the two top houses aka the most exclusive obviously it's hard. Probably 80% get dropped after the first day

No its not hard, I preffed at both of their houses and chose the house I am currently in. I'm not rich or from any of those places mentioned, yeah I'm blonde but theres blondes in every house. Honestly the reason they liked me was because I am really outgoing. I loved them back as well until pref round when I just felt like they were very fake. I've never been happier with the decision I made to not be in either of those houses lol

Most girls pick the house they feel most comfortable at. Rankings DO NOT MATTER. literally if you even care about rankings one but you're guaranteed to have no friends or a social life because people will see right through you.

If you're outgoing and easy to talk to, you'll stay in those houses. Being skinny and pretty is obviously a plus for them and no one can deny that. They are NOT the top recruiters by statistics. GPhi and KD over the past few years have been the houses that drop the most in the first round.
The amount of girls dropped is determined by a system of how many girls try to drop that house after the given round. Last year not a single girl dropped GPhi, therefore they had to drop the most girls. It's a complicated system, but it explains why Theta and Pi Phi don't drop the most. Girls do drop these houses because they do not feel they will fit in with the stereotypical beauty and/or see these houses as superficial.