I think $1 million is a thing that will happen, many analysts believe $1 million will happen in 2 halving days i.e. 2024 and 2028, and I think it's normal that in a maximum of 10 years the price can reach $1 million, this is because of the number of active bitcoin users around the world continues to increase.
It is not impossible since Bitcoin value is always increasing from one halving to another halving. But no one knows on which halving the Bitcoin price can reach $1 million. Although there are some analysts who state that $1 million can be achieved in the next 2 halvings, I think it is purely speculation only. No guarantee for $1 million in 2028 or 2029, even Satoshi can't guarantee it. Sure, the number of people who are involved in Bitcoin keeps increasing, but it is not the only factor to trigger Bitcoin value to grow significantly. If there is much bad news in the future, the price growth can be a bit slow or even free fall. Moreover, we must have bearish seasons in the future, it is the time when Bitcoin price tends to drop.
I think "speculation" part comes from the fact that it has gone up nearly x10 from bottom to top each time it had a halving, and that's at least, a lot more usually. The last bottom we had was near 15k level, so the top could very well be 150k give or take, could be a bit lower or higher we really don't know and that's just one halving, with the other halving we could "maybe" reach a million depend on what the bottom will be.
I think halving is a good place to start, because with that, it should be doing fine, it wouldn't really be that bad to reach. That would mean next year there is one, and then 4 years after that another and 4 years after that the third one, so it's about 9 years, give a year for the benefit, so it's 10 years. That means we could be x40 higher in 10 years. Can't see anything else profiting me that much.