yea it sucks, it used to with the old classic google map, had access to stuff like my maps and then it all changed when something at google changed.
For myself only, I've been updating my contacts addresses so that it carries with me with whatever contact system I transfer to...
in terms of saved maps for like vacation travel (I tend to do a lot of those) I don't tend to revisit the same places and when I do, I rebuild a new one, referencing the old google maps one.
I've been doing it over the past years though, so I don't know of a one shot solution if it exists at all.