1) most probably bitcoin will not NEED TO SCALE to full currency usage scale, because bitcoin is ill defined as a currency (it is a speculative token for speculators, not a currency for buying coffee - it is not ideal money).
Bitcoin is ill defined? Maybe. But for a starter it's not so bad.
Unfortunately at this point there's too much money in the game and the changes are made slowly and with extra care, and even so the resistance is huge.
But you are right. Bitcoin is far from perfect (see? it sounds much better than "ill defined") and it still needs to evolve.
Dogecoin may have been designed as "coffee money", something small and inflationary enough to allow everybody have it.
Bitcoin is closer to assets and gold than "coffee money", but since we have so many altcoins it's okay. Really. At least for now. You can buy online goods with Bitcoin, you can pay bills, even paying for hotel rooms is okay, as long as there are no spam attacks.
Block size isn't important.
From what I've read here and there bigger blocks open a door for more problems in Bitcoin, that's why core devs tried to avoid it. Maybe smarter people can tell on better words.
That's why actually and technically block size is important.
What is important, is how many transactions per second 2MB and larger block sizes can yield.
Yes, Bitcoin has to support more transactions. Or at least support the real transactions (yeah, I know, how to decide that?).
Back to coffee money.
Even if tomorrow Bitcoin blocksize will not be limited (keep only the technical limitation, 1GB?) it will still not become coffee money. And that's because nobody will wait an average of 20 minutes until a transaction is confirmed. For that another step of evolution is needed.
If Bitcoin does that in time, fine. If it doesn't, still fine, there are plenty of altcoins that want to fill the gap.