I had the same issue with my new iPhone SE 2020. Battery was incredibly disappointing for what I’ve known from my Apple products. I could see the battery percentage ticking down just reading articles (as some others described “a percentage point every 2 min” or so). Like others on here, I did the typical battery saving tips. Biggest clue for me was the first day I took it to work. I don’t have time to look at my phone at work except during my lunch. By the time I got home after 11hrs, I only had 20% battery life. Battery usage indicator told me that Apple Music was responsible for 87% of my battery usage. However, I had only looked at app for abt 3 mins during initial set up of my phone— never actually used it. The rest was background activity (even tho I turned off background app refresh for all apps). As a result of this finding, I uninstalled the Apple Music app. This DRASTICALLY improved my battery life. Next 11hr work day, my phone had only dropped to 78% with light browsing at lunch and a few txts. I used it to browse some social media/watch a few videos at home, but decided to keep off charger overnight. I’m writing up this comment right now with the phone having been off the charger for over 26hrs and I still have 34% battery life. This is much more inline with what I expected given how much i leave it in idle. Wondering if anyone else has the same issue with the Apple Music app possibly going rogue... uninstalling it helped me tremendously.