"The cost involved in making a transaction is skyrocketing, the rate at which transactions can be processed is very low and even now there exist many tens of thousands of transactions that are unconfirmed by the network with them even getting dropped after a couple of weeks. And even in the case you describe it is still just an intermediate store of value, you're going to convert your local currency to bitcoin, transfer it to another location and then convert back to the new local currency so you can actually use it for something because bitcoin itself is not useful."
A. The costs can be mitigated, either simply by increasing the blocksize, or through side-chains. There are discussions/competing ideas, eventually the problem will be solved. I'm actually OK with the transaction costs remaining high, it will cement bitcoin as a store of value rather than a currency, while side-chains and/or altcoins take up the currency slack - many of them are far better suited for it.
B. The cheap-asses who tried to pay lower fees get what they deserve. They existed back in 2013 too, I was one of them. Took 2 weeks to get my BTC back, lesson learned.
C. Western union converts your 'dollars' to electronic bits, sends the bits to the other side of the world, reconverts back to dollars, and then you have to go convert those dollars to local currency. I send money to family Eastern Europe all the time, the stores don't take US dollars any more than they take bitcoin.
But that is an aside to the fact that bitcoin has no use outside of being a store of value, other stores of value (gold, diamonds, land, etc for example) have many uses which is why they have value. Their value changes based in part on speculation but also as supply and demand for the real uses of those commodities fluctuates. Bitcoin's value changes purely on speculation because it has no actual usefulness.
You just proved my point! None of the stores of value you mention are easily portable. In many instances transporting such is either outright illegal and/or must be declared for inspection/investigation.
Moreover, these 'stores of value' are often just as much hype as you decry bitcoin for. Retail diamonds are priced purely on market manipulation, hype, and marketing. Industrial diamonds are cheap as hell - you can get them on Ebay for $5.50/carat. Gold's price is NOT based on its utility, in fact only 12% of the global demand for gold is industrial/medical use. The rest is jewelry/wealth storage, and that wealth storage is based on its social acceptance and its limited supply/stable production.
Land is only valuable based on commercial potential - cropland, mineral rights, or proximity to urban centers for business/residential development - and that too is subject to bubbles and market shifts, not to mention it's not easily convertible to cash.