Copying local files doesn’t magically create more stash space. Not for D3 at least.
On consoles the stash is 350 item slots. “Size” of the item is irrelevant. On PC one tab can take 35 two square sized items, as such the console stash equals 10 tabs on PC, meaning it’s smaller.
OP likely isn’t genuine.
Brand new account, spammed post across three forums (two of which are support forums when nothing would come of the request), and… 200 tabs?
Hook, line and sinker.
It is possible. If they went to class specific tabs, they could run the total over 40.
Totally agree. Especially with the addition of SSF mode. Char slots get spread too thin with SC, SSF SC, HC, and SSF HC.
On the server side it loads all the specifics of all the character files in the game. They also store all the specifics of your account on another server. It’s certainly possible to add more but it requires more resources. I expect the true reason is that it costs money.
That’s pretty much always the underlying reason. There’s very few things that can’t be fixed, a hell of a lot of those who can aren’t worth spending the resources on though.
Why does it matter if someone wants to keep something that doesn’t have a practical use? There is nothing wrong with keeping things that don’t have a use. No one needs to justify why they want to keep something or a lot of things.
If people keep junk and run out of space that is on them. “I might use this five years from now, I better keep it.”
Yep, kind of like the extra hardware that is left over from assembling something, you dump it in a container, put it in the garage, only to discover it a few years later rusting. 
I have a box in the closet that has stuff in it from 20 years ago that I have never used.
Last season was a ton of fun. It was the most I have played in a season since S1. Midway through, I set a goal to push all 42 of the solo leader boards (I still do not have Necro DLC).
Trust me, I had to do a lot of stash tetris to accomplish this. I had to use each char as a mule after I geared them up along with using 6 characters worth of followers as mules. There definitely was not enough stash tabs simply for the 6 most common builds for each class, much less a fun off build.
Some people’s version of fun is to play only one build ever and only need 1 stash tab. Some people like to play many different builds and classes. Some people simply like to collect stuff, such as maybe trying to get a Primal version of each piece of available gear whether useful or not.
Your version of fun is different than my version of fun which is different than everyone else’s version of fun. Yes, 200 stash tabs is excessive for even the hoardiest of hoarders, but 25 is not, and 13 is definitely cramped for a lot of players.
Many of us remember when they tried to give us more and they said they could not do it. D3 will be going into maintenance mode in a few months, so asking for something we will not receive is futile. I also remember people coming to the forum to complain about stash when they did not even have the 5 from the seasons. I always thought 20 would be good but it was not to be.
Why are you so defensive? A big fan of hoarding?
Yeah, they used the same lame pretext.
Have you seen streams where people played PTR in 4 man party and filled entire towns with items from the goat vendor in search for primals? Nobody ever got a crash from it.
No idea why they didn’t make a real stash for D4. They even designed items which were supposed to be keepsakes for the campaign and no way to store them.
Why can’t I make several builds for each of my characters and store all the required items in an easy and organized way?
The solution is of course, play one character for season and wipe everything at the end. But it’s highly unsatisfying.
Could it be because items on the ground aren’t stored the same way that items stored in the stash, inventory and equipped on the characters are stored?
25 tabs lets you keep 12+ full builds per class in the stash with room to spare. You really don’t need 200 for that. Hell, the current 13 is enough space for all the “main” builds for all classes.
I want infinite stash tabs like D2 with plugy for infinite fun
And I want a supermodel like (insert your choice here) for a girlfriend. I got a better chance of that happening than getting more stash tabs in D3.
(0.00000000001% chance > 0% chance) 
I’d love more stash space