In reality, there's no need ever to add more Bitcoins. It would make far more sense to add more decimal places to better facilitate micro payments as more and more economic energy piles into Bitcoin
There is no adding more decimal places. However, there is a proposal to move the period six columns to the right, ending up with two decimal places instead of eight. The resulting unit is to be called a bit, composed of a hundred satoshi. 1.00000000 BTC (one Bitcoin) = 1,000,000.00 bits (one million bits and 0 satoshi) = 100,000,000 satoshi (one hundred million satoshi).
Thus, if you have a total balance of, say, 7.05893808 BTC, that is equivalent to 7,058,398.08 bits (seven million, fifty eight thousand, 398 bits with 8 satoshi, which is something you can actually pronounce).
Note that, if we switched to speaking about bits, the current exchange rate would be around 4,000 bits per USD (if we assume $250 USD/BTC). As in, right now you could buy yourself over 40,000 bits for $10.
Also note that, if 1 bit were worth 1 dollar, or equivalently, if 1 satoshi were worth 1 penny, then 1 BTC = 1 million USD.
One of the reasons to increase the total number of coins is to remove the long-term deflation pressure. That is one of the issues possibly affecting Bitcoin that is pointed out by Varoufakis.
If you have come to the conclusion that long-term deflation is an issue for Bitcoin, you are free to join Varoufakis in staying away from it. Fixed money supply is a central and deliberate aspect of the protocol, well-thought out, and effectively unchangeable in the foreseable future.
blockchains are a friggin database technology, 5 years down I doubt any users will care what the underlying network token is.
Not inclined to take predictions for the next 5 years by someone born in 1994 and who has an obvious stake in one particular outcome.