1 BTC being still equal to 1 BTC? I can give two shits about that.
Really I never understood what's the point of repeating that all the time.
Btw, 1 USD = 1 USD. So what?
1 USD= 1USD
sure.
Do you know the meme of the emptying cart, this well explain that even if 1 USD has always been equal to 1 USD, the true value (something similar to purchasing power) has been going down since inception (or 1971 at least).
So once again,
saying 1BTC=1BTC you are implying your numera ire, your basic unit of account, is the BTC, not the dollar.
Your numeraire, your store of wealth, is the BTC, not the USD.
You are not investing USD in BTC (and price is going up).
You are investing BTC in USD (and price is going down, hence, don't hold in USD more than you are willing to lose).
When you increase your Bitcoin account you are not buying BTC! You are selling USD!
This is, to me, the true meaning of this sentence.