Delaying deletions can result in significant memory overhead [1].

TANSTAAFL, as they say.

[1] https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&d...

That isn't a choice though. The high performance garbage collector is implemented by the language implementers and comes for free, while the delayed cascading deletion has to be done by the individual programmer not the language designers.