It's definitely neat having a lot of cabs, and if it's something you treat as a hobby with stuff like deal hunting, finding period-authentic accents like carpet or tokens, restoration, and finding buyers, then I can definitely respect that, playing the games themselves is just a nice extra after the fact.
However, from a practical standpoint, it's your business if you want to have an arcade's worth of machines, but personally the most I'd want would be a generic JAMMA cab with a stack of PCBs, and maybe two other unique cabs that I already play a lot with a lot of room to grow your skill (DDR for example).
So in other words, a part of me hopes that people like the guy in the OP's video are actually good at almost all of their games. At the least, he opens up his house for others to play in, so there's that, but the idea of someone out there who doesn't do anything like that and just accumulates machines and can't 1CC a single one of them, that's kinda sad. Hopefully it doesn't happen quite that often.