Reselling is a huge bother (either you get a fraction of the price at a place like GameStop or you have to ship it out yourself & use a site like eBay). Just be more careful with your purchases.
Who does this who isn't a broke kid in school?
Can't keep in case store is shut down later and you can't redownload
I've had way more instances of a physical copy failing on me than of a digital storefront shutting down.
Higher "on launch" prices for games
Most non-AAA games have a launch sale on digital, you generally don't have to pay sales tax, and you sometimes get a rebate back (like with Nintendo). The post-launch discounts tend to be more frequent and deeper on digital as well.
Other reasons for me:
You can buy digitally anywhere in the world (I'm a digital nomad). Before that, I lived in a place in the US where it was about 30 minutes to the nearest game store so it wasn't that convenient to buy physically either.
Digital games come out when they say they're coming out. I've had more than one instance where I tried to buy a game physically at launch date & the local store hadn't gotten it in yet or my shipment hadn't arrived yet.
Physical copies are the worst on portable systems. It's great being able to have dozens of games available to play on a portable system at any time.
No worries about misplacing a game or having it die on you.
In some instances, you can buy a game digitally once and have it on multiple systems. So like I can buy a Switch game and have it on the family Switch but also have a copy on my Switch Lite. Or like with Sony, you could attach your account to 2 Vitas so I could buy a game and stick it on both my Vita & my oldest daughter's Vita.
No regret from selling a game and then wanting to play it later (but now it's hard to find or the price has gone way up).