Soldered RAM lasts as long as socketed RAM.

Yes, roughly the same. Both are solid-state chips with no moving parts. Under normal use, you’re looking at 10+ years easily — long enough that the laptop or motherboard will be obsolete first.

The real difference isn’t lifespan, it’s repairability.

Socketed RAM can be swapped if it dies or if you want more. Soldered RAM is stuck. If a soldered stick fails, you’re replacing the whole board (or device). But failure rates are low for both types — RAM doesn’t tend to die unless you cook it with poor cooling or get a factory defect.

So don’t stress about the lifespan. Stress about whether you’ll be able to fix it later. If you can choose, go socketed for future flexibility.