How to save RAM in iOS?

Question

iOS

An old iPhone with 1 GB of RAM and the latest firmware (12.4.2) works fine, but heavy applications crash periodically. These are all sorts of 2GIS and other applications with maps (call a taxi, food delivery, transport, navigator, etc.)
Is it possible to somehow reduce the memory consumption of the system itself and services? I understand that there are no other ways to improve stability, well, except for buying a new iPhone.