Plainly you haven't done much with 22 LR , you should look into the true facts ! Personally i have put eight through a single bullet hole , i didn't miss with two more because i seriously thought something had gone wrong . More expensive than slugs? Dont really know but few will buy less than a a brick a time ( 500 rounds) more than slugs ? Don't know tbf perhaps but they are far from expensive the cheapest stuff you can get for any powder burning gun . Reliability and life ? pretty much forever had mine above 20 years , never changed a part never had an issue . Really cannot say thats the case with PCP from when i competed in FT and HFT events .
I bet there are loads more guys on here running RF than PCP . Again £150 up SH ( lot less at auction) will get you a good one , would that get a Spanish made BSA ? nothing that really wears out and no leaks to sort , charging gear to test / replace
The airgun remains the boss inside Barns culling Ferals and rat or in suburban gardens though . 5 fps variance or less on my lazerglide built to my detail by Steve Pope I am no airgun hater , just saying how it is . The 22 LR can shoot ammo designed to be just as powerful as 15-20 ft lb right up to the HV stuff like my favourite CCi Velocitors that take 100 yard shots just as good as my 22 hornet , 223 etc etc and very useable up to 140 . Go on the U-tube and you will find folks shooting much further on paper .
Do check out what decent 22 rf fetch SH the price of a brick ( 500 rounds ) and how well they shoot without very much maintenance indeed any maintenance at all in the hands of many