That “couple decades of software running on personal computing hardware” was the time when whole families had only one computer in their household. Maybe two if you’re lucky. And certainly no smartphone.

Now, every person has their own laptop, phone, probably tablet, and maybe watch. And they expect them all to access the same data, whether they’re at home or on the go. 

Networking might be better now, but proper network security is far too complex for your average (or even above-average) person to host a home server that can be safely accessed externally. 

And the software isn’t really there yet either. Projects like #start9 help, but the big corporate services (Google, Amazon, Microsoft, Facebook, etc.) won’t give up easily and will always have better funding than any open source project. 

Doesn’t mean we shouldn’t try. I think it’s a worthy goal.

Tl;dr: Yes, the hardware is good enough. No, the ecosystem is not ready for it.