I still beleive that the most brain wallets are not serious wallets, and used for test/education/fun transactions. For these transactions (as well as for some quick transit transactions) no need to create the crypto secured wallet, and the brain wallet is used.
Of course there are some real wallets generated in "brain wallet way", but such wallets can be counted on one hand.
By the way, what do you think about
time locked wallets based on easy brain wallets? Let's say we take the easy passphrase "
bitcoin", hence the corresponding brain compressed address to it is
18VkRiDhFu2Z17AvtpU3vL2LbTXDzCvDVo (this address has already been used of course).
However, we take the public key of this address (
02218ad6cdc632e7ae7d04472374311cebbbbf0ab540d2d08c3400bb844c654231) and create the time locked wallet (for example with the help of this tool:
https://coinb.in/#newTimeLocked), let's say with time lock 31 December 2019:
https://coinb.in/?verify=0450650a5eb1752102218ad6cdc632e7ae7d04472374311cebbbbf0ab540d2d08c3400bb844c654231ac#verifyWe receive the P2SH address
3NTavRnFZHkMmSFYVMz5PPb48WsNyVszDW, which could be accessed only by both
redeem script and
private key/signature from that easy address (
18VkRiDhFu2Z17AvtpU3vL2LbTXDzCvDVo). The redeem script will not by available in blockchain till the funds are released from the address.