In 2019, the best camera might be the one you have on you at the moment. Since the release of the first cellphones with cameras in 2002, technology has gone through a drastic metamorphosis. Long gone are the days of sub-megapixel cameras that produced images you could hardly call acceptable. In 2019, cellphone cameras use bleeding-edge machine learning technology to create better photos all within the press of a button. Modern cellphones are in many ways much more advanced than the crème de la crème of professional photography equipment. If you're looking to start taking better photos or if you're a professional photographer with years of experience, you shouldn't underestimate what your cellphone can capture.
Apps & Connectivity
First and foremost, cellphones have access to the internet and apps. DSLR shooters know the struggle of having to wait until you get home to import and edit photos before they can even consider posting. While some modern DSLRs can transfer photos to your phone, the apps aren't very reliable for many people and don't always work (looking at you SnapBridge).
From my Google Pixel, a phone that was released in 2016, I can snap a photo in RAW format, color grade and edit it in Lightroom or Photoshop, and have it shared to my friends in a matter of minutes. If you're not sure how you'd like to edit, there are tons of apps that come with creative presets to kick-start creativity.
My Pixel also Geo-tags locations for me so I can keep a map of where I saw things in each city I visit. While many people won't use this feature right away, urban explorers and hikers will appreciate having a photo map showing where they've been and what photos they took at specific locations.
Portable & Convenient
Something else worth considering is that your cellphone rarely leaves your person, its one of those items you take with you everywhere. For me, this is a big deal. I normally shoot with a relatively bulky Nikon D700 and a 24-70mm lens, that's a lot to carry around all day. While my DSLR might offer better quality in some specific scenarios, my Pixel will usually be much faster and good enough for the job.
Cellphones make photography a lot easier for anyone who doesn't want to carry the extra 2lbs on their shoulder all weekend. Of course, you do lose some of the benefits of DSLRs like interchangeable lenses, but you don't always need a 300mm zoom to get the shot you want. Pulling out your cellphone is also a lot faster than pulling out your DSLR for a quick snapshot. With your cellphone, you likely won't miss the moment.
Better Video Wins
Budding videographers may rejoice as many modern cellphones completely outperform entry level video rigs. Most modern cellphones cameras are internally stabilized to negate the effects of shaky hands. Stabilization is specifically useful if you want smooth video or sharper pictures in low-light situations.
Video makers will also love the fact that many phones are capable of shooting 4k RAW video. There are a few apps on Google Play and the App Store that allow you to color grade and edit such video files as well, though you're probably better off using a full computer (or at least an iPad) to efficiently edit 4k video.
If you want to shoot raw video on a "professional" camera, you're looking at a bill totaling well over one thousand dollars for a camera, lens, storage, stabilization, and extra batteries.
Take the Picture
Lightroom Mobile (a free app). They aren't the greatest photos in the world but they do look good enough to convey the beauty of each scene. I even have a 5x7 print of the National City Christian Church hung up in my house and it looks great.
Don't make the mistake of thinking you can't make great images with what you have right now. Photography has never been about the camera, it's always about the relationship between a scene and the person capturing that scene. A cellphone can be all you need to accomplish your photo goals.