^^^ Agreed. Once I discovered my 5s's battery was not holding a charge as well as it once did, I rang some shops to find out who could put in a new battery for me, how soon, and for what cost. I was shocked by what I was told.
First stop was Best Buy. They said they had stopped servicing the 5s a good while back and had no parts for it. Then, I contacted some smaller shops near my home, and I was told the same exact thing. I could have spent a lot more time trying to search out a shop that might still have a battery in stock for it, but all things considered, why bother?
The only option I had was to send it to Apple to replace the battery, but the cost to do so would have been $50+, and I would have had to do without my phone whilst it was sent to them, the battery replaced, and then the phone posted back to me. I could have lived with that if I thought the phone was going to be supported another 3, 4, or more years, but I knew it was becoming too old for Apple to support it. iPhone 11 had already been released, and I was still using 5s. As much as I wished it was not so, I knew it was time to move on because everything else aside, my first thought was that Apple was not going to support the 5s for more than one more year at most. I could pay for a battery, but why do it if the phone was not going to be supported for more than 10-12 more months at MOST. I would have to get another phone by then anyway. Better to put that $50+ toward a new phone, which was what I did. The cost of a new battery equaled the tax paid on my new phone. It was definitely the right decision but hardly rocket science in deciding it.