My old galaxy s7 was getting about a half day on light use by the end. About 1 hour with heavy use. Don't remember how long I had it, but I'm guessing about 4 years.

The USB port wore out too and wasn't repairable individually. Repair would cost more than the phone was worth at that point.

Battery replacement and repairable design is a very important matter. Moores law doesn't hold true anymore, and devices can stay relevant for a long time if manufacturers don't force obsolescence

I wouldn’t worry too much either way. We won’t get back the plastic pop off backs of yesteryear. While “removable batteries” get the most clicks the rules aren’t really regulating phone design, but try to reduce e-waste and force OEMs to plan for recycling batteries. The part about removability is a soft “should”, while there are hard “must” quotas for circular battery usage and recycling. Apple will probably need to stop their practices of DRMing batteries (which they already partially did in the EU, as far as I know, I switched the battery in my old 12M, before gifting it and iOS didn’t raise any warnings about the battery). But implementation of non-binding EU rules into national law is susceptible to interpretation and OEMs will lobby heavily. IP68 rating is here to stay, so is adhesive, I can imagine you don’t need special tools, but still need to release some screws and adhesive before swapping the battery in the end.