I now have all my photos stored on Microsoft OneDrive. I ran out of space in the various free accounts that I was able to create, and I needed more storage. I looked at the options for cloud storage and selected OneDrive, as the most reasonable option available. OneDrive is a Microsoft product so it is unlikely to disappear any time soon. OneDrive charges $50 per year for 100 GB storage, which was what I needed.
OneDrive allows me to copy specific directories and then access them from different locations, including other computers and from my phone. Unlike some services, OneDrive is not designed as a computer backup system. It does, however, store an additional backup copy of my photos, in case something happens to the external hard drive that I routinely use.
The OneDrive PC application and iPhone App are easy-to-use. I encountered no problems, although it took about a week to transfer all my files to OneDrive. Fortunately, OneDrive keeps you well informed about the progress of your transfer and clearly marks transferred files with a green check mark.
My timing for this change was not good. A few days after I made my decision, Google lowered the price for their competing Google Drive service to $1.99 per month or $23.88 per year. Consequently, when my OneDrive service comes up for renewal, I will probably change to Google unless Microsoft has lowered its prices by then.