It is trivial to have a new ip address, requires only minutes, but getting a new phone number is much more work, and also capital intensive. This places a huge barrier that only gets more successful over the years (as an increasing number of phone numbers are blocked) against bot accounts. But it does not hamper legitimate gamers at all (because, frankly,MaplestoryM Mesos in case you have a computer that can run MS you've got access to a phone of any sort ).
I know that there are a number of disadvantages, but I don't believe they're big enough to justify not implementing this system. The biggest disadvantage I can see is that a bot/meso farmer uses your contact number and has it banned until you attempt to make your account.
In that case, there could be a fairly intensive approach to clear a phone number (it would have to be intensive to be a successful ban). Either that or you're out of chance, but the probability of that happening anyhow are slim to none to begin with.
Additionally, nexonNA could automatically ban phone numbers from all countries outside of the serviced nations, thus making it even harder for chinese meso farmers to operate (they'd need a massive source of American/canadian phone numbers and corresponding telephones on hand to make additional bots).
Ok, I know I've written about Hayato a few times in the past, but I really, really feel he's rather underpowered. He is, basically, a fast-paced buy Maplestory mobile mesos mobbing warrior. His 1v1 skill, Shinsoku, seems fairly underwhelming, even with Hypers believed and even a decent bit of funds. This endangers him worst, frees him at least for most major bosses (Empress, Hard Magnus, to mention two ).