... Not caused by ram ...
iOS devices have never been advertised for multitasking. They run one app or webpage at a time. It has always been this way. The NAND flash inside these devices is not compareable to ssds inside real computers. There is no swap or proper memory management. The soft- and hardware architecture is note geared towards a reliable multitasking workflow.
Complaining about the inability of iOS devices to keep browser tabs and apps open without refresh when switching between them, is like complaining that your screwdriver is such a bad hammer.
Erm. But I never had an issue before on any of my other devices. Multitasking worked and never experienced freezing.
In any case multitasking should not be an "advertised" feature of any device but a default process of any modern smartphone.