It's much less expensive and you will never bother with specs anymore, the servers will make all the work to improve their infra and you won't bother to upgrade your PC each 3 years
You also don't need to have that ugly boxes that are PC using your space, you can connect direct from your TV, though this is a non factor for me
Personally I can make a PC last the better part of a decade. Like if I buy a PC I'm not upgrading it ever and I'm not replacing it for 7 or 8 years either.
If you're the kind of person that upgrade your PC every 3 years then streaming will NEVER live up to your crazy high expectations.
And if you're the kind of person that thinks all PC gamers regularly just upgrade their PCs for whatever reason... then you're just silly.