My average is a board a month, sometimes up to 2 if I really like the board.
I'm skating almost every day for roughly 1 hour minimum and 4-5 hours at absolute most on weekends nowadays. A $lave board last year lasted me about 3 months but there were 2-3 weeks of wildfires that kept me from skating it though.
I'm surprised people go through boards faster than a month if they're not doing low impact stuff or are only doing what they know. I know some people are more sensitive to chips and razor tail, though, but still...
My boards last me a long time, mainly because I skate like a grandma these days and have multiple setups - more so transition / small fun things and no rails, gaps, stairs.
Others I skate with who always go hard (stairs, rails, gaps, and just hard skating) can go through a board in a day or even a session, but more commonly a board a week is about their average. Those guys usually always have spares floating around and older boards they have taken off as back ups just in case their main board breaks while they are out.
I couldn't justify buying and destroying pro boards, even at wholesale prices for that sort of skating, but they are happy on the wholesale blanks program so when they buy boards by the box, it works out way cheaper.
For me the quality over quantity works much better and I try to look after my boards a lot, but if something feels off or weird, I will retire it straight away and pass it on to someone else, rather than keep skating it and not be happy with it.