They don't. They both have their good and bad points.
|One of these things is... much like the others, really|
The batteries never go flat in a paper book, but you can't adjust the text size or contrast. If you want to read a paper book in the dark you'll need a light of some kind, but depending on the device you're using to read your ebook you may find the illuminated screen causes eyestrain or insomnia.
There's nothing like rummaging through the cheap book bin at an op shop and finding something good in among the old Dolly Fiction and 70s cookbooks. But with hard copy books you're limited to what's on the shelf or what you can have shipped to you, and transporting paper books takes takes time, money, and fossil fuels. On the other hand the sheer size of the internet's cheap book bin means poking around without a clear idea what you're looking for is unlikely to dig up gold. But if you do know what you want and it exists digitally, you can have it right now regardless of how old it is, how obscure or unfashionable, and how many physical copies exist.
You can store a whole library in a digital device, but it's not socially acceptable to perve through someone's Kindle to get a snapshot of their personality the way you can snoop on their bookshelves. And bookshelves are lovely, but physical books are bulky and heavy and if you move around a lot - like I have - sooner or later some of your precious collection is going to either get damaged or disappear without trace.
I've personally never understood the excitement about "old book smell". Maybe it's a sensory processing thing. Or maybe it's because my own old books are mostly either bought from op shops or have spent years in cardboard boxes under relatives' houses, so they smell less like vanilla and ancient wisdom and more like cat pee and mothballs.
(Another thing I don't understand: the hate for organising books by colour. They're your books, sort them however the hell you want. But if you're buying books specifically for the colour or to use as decorations rather than to read, maybe it's time to look at your life choices.)
You can underline things and make notes in the margins of physical books more easily than you can in digital ones, but you'll have to get online or use other books to check references, verify facts or look up unfamiliar words or ideas. My Kindle is an older model and not built for internet browsing, but it has a built-in dictionary you can access by pressing down on the word in question and can usually cope with a quick visit to Wikipedia.
Reading's not just a very good way to pick up useful knowledge and skills, but it exposes you to different opinions, point of view and experiences. It can take you to different places and times and give you an opportunity to walk in shoes very different from your own. Reading is important because the words and the stories are important. The format really isn't.
So use whatever works for you.