And I mean really, really lost.
A lot of people can't remember their passwords after 4 minutes since they set it up.
But apart this, there's several ways bitcoins can get lost, like in example if you have a wallet on a USB key and this breaks and you have no cold backup.
This will inevitably bring, in the future, to less than those 21 million cap.
And they WILL keep going down.
Is there a plan to reintegrate them?
you need not worry about the future when the 21 million cap is reached because it is far far away.
also the price of bitcoin will determine whether the amount of available bitcoin is enough or not, besides there is not just 21 mil
BTC there is much more because you have to consider every digit after the point too. i mean 1 satoshi (1e-8
BTC) is usable and have value.
additionally 1 satoshi can be broken down into smaller units if needs be, with a simple change in the code.
I agree with this: it's not an actual problem. It may become a problem in the future.
But if what you say is true, that also Satoshis can be divided, then there is no problem at all, I guess.