Good comparison.

But I was writing my Ph.D. dissertation
just as daisy wheel printers were becoming
popular. Then there was no doubt: I
typed my dissertation into a text editor
on a computer (I was from my
non-academic work already really good
with those two tools)
and printed it out on a
daisy wheel printer.

That approach
was much better
than a typewriter because of the accuracy
(I have horrible aptitude as a typist and
desperately need the power of a text editor
and computer to make corrections),
the speed (could
get a new copy at 30 characters per second),
and could make revisions quickly and
easily, and I made a lot of
revisions before I handed in
a copy. Then for a prof I had
to add a few words of clarification
to a paragraph -- did that, printed
the whole thing again, and returned
the result to him on paper in
24 hours. Yes, the only place I could
do that word processing was at my office,
but that was
still better than my typewriter at home.

More generally, one of the most important
uses of computers has been for document
preparation, and that is still a big
need, if only for a post at HN where
I'd much rather have my computer than
a smartphone.

I might have become a tenured prof, but
the main bottleneck was just getting
my academic mathematical
word whacking done. Net, I couldn't
do it. Flatly. No way.

The word processing
group of the university I was in
couldn't do it. I couldn't do it
with just a typewriter. Halt. Full
stop.

Doing the academic research? Fun and
easy. Writing up the math? The same.
Getting the typing done? Just impossible.

Now I
can do mathematical academic word processing
with my good set up
on my PC of D. Knuth's TeX, etc. For the last
paper I published, after I gave up
on being a prof, I used TeX -- it
worked great.

But, sure, a smartphone wouldn't help
with TeX. TeX on a smartphone? F'get
about it.

Net, a PC is a great tool, for many
things, e.g., nearly all of document
preparation, much better than a typewriter,
even though a typewriter has some
advantages as you point out. For nearly
all of document preparation, the extra
cost, complexity, etc. of a PC
are very much worth it. Really, net,
PCs replaced typewriters.

So far I have no use for a smartphone.
One reason is that I stay at my PC
working on my startup. My phone
is right here, with its signal
running through my PC's FAX modem card
so that I can use my text editor
to find and dial phone numbers --
also save phone numbers.

In time a mobile device may replace
a PC. But need:

(1) A good replacement for a keyboard.
Maybe voice or brain waves would
work if can reduce the detailed
complexity of much of current
keyboard input, e.g., HTML and CSS
markup.

(2) A good replacement for a mouse,
and a finger on a screen is not good enough.

(3) A way to view output much better than
a small screen. Sure, may be able to use
some special glasses. Sure,
if 3D is to play a big role, then
special glasses may be the way.

(4) Appropriate versions of, or
replacements for, a lot
of crucial PC software, e.g.,
my favorite text editor, Knuth's
TeX, PDF writers,
lots of old programming languages,
libraries, source code, etc.
I have a lot of such I very much
do not want to be without.

(5) Backup, say, to the cloud, that
can trust enough to replace
tape, writable DVDs, external USB
hard drives, etc. Lawyers
are a biggie threat.

(6) Have enough trust in the
Internet finally to depend on it
nearly totally.

(7) Solid solutions for the
many, severe security threats of
mobile devices.

(8) A way to get data to replace
getting data just by saving
Web pages. E.g., when I
shop for or buy things on the
Internet, I want to keep
the associated Web pages.

Sure, maybe (1)-(8) will come.
E.g., for storage, maybe
some of nanowires, what HP is
doing, etc. will mean that
all my storage can be in little
cubes, about the size of a sugar
cube, I can write and store
in my side desk drawer,
also on the Internet in case of fire.
Also stick under the insulation
on the floor of the attic where
no way can lawyers find it.

But, just for now, biggies are
some comparatively simple things --
keyboard, mouse, screen, laser printer,
DVD R/W, and a few more. E.g., I
still use my laser printer for
some crucial things. Indeed, I
still keep my daisy wheel printer
as the best way to address
envelopes for USPS -- they
are still in business, not yet
totally replaced by the Internet.

Here's another thought: PCs are
here and so far there is nothing
to replace them.

But as it slowly becomes possible
to replace PCs, they
will be replaced not
by mobile devices but slowly
by a sequence of incrementally
better PCs,
some of which might
have form factor and power requirements
to permit being mobile.

Over time,
maybe it will be possible to
replace PCs. Sure, Windows XP
replaced Windows 3.1 and PC/DOS --
that was incremental as I
believe the replacement for a PC will be.

In strong contrast, smartphones
and other mobile devices won't replace
PCs, at least not for a while.

Look, A16Z, there are some uses
for smartphones: Teenage girls
are genetically compelled to gossip,
24 x 7 if they can, so
need at least cell phones.
Nearly everyone who works from
a panel truck wants at least a cell
phone. Cell phones are a good
replacement for the radios
that taxicabs used to use,
and now smartphone are crucial
to Uber, etc.

But for the billions of smartphone
users, the reason was simpler: It was
much cheaper just to put up cell
towers than to lay copper cable.
Ergo, smartphones instead of land lines.
But don't expect that several billion
people in mud huts will be using
their smartphones to order
four feet wide TVs from Amazon.

With some irony, as the Internet
improves, the need to move around
will lessen and, then, so will
the desirability of being
mobile.

Or, having two locations,
one at home, and one more at an office,
and driving between the two,
is a bummer -- waste time, money,
and energy. Being mobile
is often a bummer.