To belatedly reply to this, yes, of course there is a benefit! Otherwise we wouldn't be doing it. For one, you risk less by having your accounts on multiple different IP addresses, meaning it's harder to catch you cheating or link all your different accounts together for a chain icing. This helps you maintain separate identities/accounts and means you have to do less manual work to do to keep your stuff secure! It also helps you set up multi account ABing in different shops, so you can either catch more items per restock, or just go in different shops altogether to maximize profits.
I love Proxifier because it logs what it does, and if it cannot connect, it won't try to connect with your normal IP, meaning if something goes wrong, you have a log of it, and it's not leaking your actual IP at any point.