If BTC is $1M, it means either than $ is worth nothing, or we are in full hyperbitcoinization (meaning that Bitcoin is the de facto universal world currency, and everybody accepts BTC).

In both cases, no point in selling. Just use your BTC as you were using fiat.

I would use it... like now.

Sell in exchange for what?

Ask yourself this. If you had $1M in fiat in 2030 would you sell?

But the answer is no. No I would not sell. I would live my life happy that I was able preserve the fruits of my labor in an asset that isn't being destroyed by sociopaths in suits.

Ofc I will sell.