It happens often that children are found and added later to a family so they get a higher ID while birthdate is sometimes earlier. When i publish my GEDCOM on a local Dutch site, children are sorted to INDI numbers which are equal to the internal ID's.
So an option to sort internal ID's according to birthdate or even to change them by hand to a not yet used number would be a nice option. This also sometimes applies to a second marriage which was found later on.
It would be very difficult to reorganize all the IDs of all individuals in the database. I am not sure though what is the benefit of this. The IDs are really internal and not that relevant. Why is it important to you?
Sorted id's are important to me because they are also used in the same order in the exported GEDCOM file which i use to publish my tree on a free dutch website. This website sorts children to id instead of year of birth.
I would consider publishing my tree on myheritage but the disadvantage is that my tree is not found by google in that way and for me it's just too expensive, i have just 520 persons in my tree just above the free limit.
it would perhaps generally be a good idea to click "recalibrate ID numbers" and the system automatically reorganizes it for some greater potential use later on.
However, the Myheritage staff says this will be a useless option. I do not agree with that. So i guess this feature will not be implemented in the future...