The house takes (Sportbook, track, casino) takes between 9-25% of every bet. So, yes, relative to those options, crypto lotteries/gambling can be set up to be practically free. That is, one can (and have) set up lotteries where there is no take (provably so) save for the cost of the transaction, which on proof of stake chains or L2s, are very very cheap.

There are many aspects of blockchain that just don't make sense, but the opportunities in providing more equitable gambling opportunities are, in a word, staggering.