Will Bitcoin replace the US Dollar?

So I was staring blindly at the M2 money supply charts from 2020—where we saw that wild 26% spike in fiat printing—and arguing with my accountant uncle over Thanksgiving dinner.

He laughed directly in my face.

I had just proudly claimed that fiat is melting ice. But then he hit me with a brutally simple question that left me completely stumped. He asked, "Will Bitcoin replace the US Dollar completely, or is it just a fancy digital gold brick for tech nerds?"

I froze. Honestly, I didn't have a solid answer.

I mean, I get the hard cap. I read the whitepaper. Last year, I actually managed to pay for my VPN subscription using a Lightning node. Setting up those inbound channels took me three days of pulling my hair out, but it worked. Still, living purely on a BTC standard feels impossibly far away when local merchants still price every single item in fiat.

Where I'm Getting Stuck

Here is the mental roadblock I hit trying to map out a realistic timeline. Can you veteran guys check my logic here?

• Volatility: My local coffee shop runs on razor-thin margins. If they accept sats on Monday and the market dumps 15% by Tuesday, they literally can't pay their rent—right?
• Taxes: Every single transaction triggers a capital gains event in the states. Buying a $4 latte turns into a total accounting nightmare.
• Unit of Account: Everything around us is still pegged to fiat.

My Head-to-Head Comparison

I sketched out this mental model to figure out the actual friction points. Am I totally off base?

I am definitely not trying to be a skeptic here (I hold sats). I really just want to know how you guys view this macro transition realistically. Are we waiting for sudden hyperinflation to force the public's hand? Or will they just exist side-by-side forever?

Help a confused beginner sort out this massive puzzle.