The article basically says that the author switched from Dropbox to Google Photos because Google Photos is better for storing photos. This is true. Google Photos is an app specifically for photos. However, what the author missed is that there are other people who use Dropbox other than storing photos, but files as well, and that, cannot be done in Google Photos.
What I use Dropbox for is for storing files of all kinds. That is not to say I dislike Google Photos. I also use Google Photos to store my photos and videos, mainly from my camera. I set it to automatically upload to Google Photos after snapping my photos or videos. Google Photos is free if you allow Google to store the photos at a lower quality, but human eyes can’t differentiate the difference in quality anyway, so it is not a loss. They also let you store information such as what device you took your photos in, where was the photo taken. Also, they have integrated machine learning to recognize faces in your photos and tag every different person in your photos and group them. They also will alert you if there are special pattern in your photos such as a weekend away at a vacation, they will suggest you group them into an album.
I bought the 1TB plan for Dropbox, that is 1000GB of online storage, many times over my overall usage, currently, at 27GB. I use it as a backup of my files. Also, to sync files across devices. This means when I am in office, I can use the same files as on my home computer. If you accidentally deleted any files, you could also recover them.
Different app has its own strengths and weaknesses. You use it depending on your needs. I use Dropbox to store files, backup, and sync. Google Photos to store photos and videos, backup, and sync. I use Google Keep to store my random notes and scribblings. I use Trello for my To Do lists. I use Google Calendar to set my daily schedule.