Not too long ago I discovered how invaluable low power mode is. I use an iPhone 11 Pro Max, and I get battery for days. I love the feature. More recently, I've been having trouble with 5Ge. Signal has never been great, but lots of lagging when loading web pages even more so lately. I usually only get 1 bar. I decided to switch to 4G and now I get plenty of bars. The speed is pretty decent too at 15mbps which is enough for just iPhone use for me. I don't notice a dramatic difference in usage, if any at all. Between low power mode and 4G, my iPhone feels like a new phone all together. Much more reliable in terms of having enough battery and signal.