different DC anon here (not op)
benefit is that diskshelfs or rackmounts are usually LOUD AF and draw a shitload of power. The power prices in DC are often lower and also they guarantee some level of redundancy with backup power generators and bat buffer bla bla surge protection and fancy PDU metrics. Aside from me not wanting a F14 fighterjet in my living room DC also has the benefit of allowing me to announce my own ip space over BGP. This isn't possible to do from your average consume home connection and even with some business uplinks it wasn't possible in the past. Here I can just do it. This allows me to take abuse into my own hands since there is no "real" ISP to complain to anymore as I am "the ISP" then. Sure they could go to whomever is peering with me but this is a very far step and I've never seen this play out they only ever do send an email at max to which you reply with some generic "im an isp -> it wasn't me -> id like to help but unfortunately no logs"-message . And complaining to IXP you can do ofc but they'd never do shit they aren't supposed to do shit.