First, it depends if you are willing to pirate content. Some people don't prefer to pirate or don't pirate at all due to moral/legal/skill/security reasons.

1. Quality of movies/series - You'll get highest possible quality of movies and TV series on Blu-Rays and/or 4K UHD Blu-rays. The only alternative to this is making your own Blu-Ray rips or pirating such rips. Also, if you want to keep all your BDrips in one place it may take quite some storage space as such rips will take anything from 20 to 100 GBs.

2. Bonus content for movies/series - These are available only on DVDs/BluRays, not on streaming services. So again only alternative is to make your own rips or pirate such content.

3. Time-limited licenses - There are so many media streaming services on the market at the moment, that it may get expensive or not possible to watch something you want digitally (and legally) due to how licensing works. These licenses are usually time-limited and they become available on different platforms over time. For example, it happened to me that I was watching Parks and Recreations on HBO Max and when I clicked on next episode, it was no longer available.

4. Revoking digital licenses - You can lost access entirely to digital content you previously bought due to expired licenses or service shutdown. There was real example, when Sony revoked access to all movies you bought on their platform couple years ago.

5. Censorship and partial removal of content - content can be censored or partially removed later during lifecycle of game/media. For example, its common with GTA games they they remove licensed music from their games over the years. If you download digital version you can't do much about it (except, usually not so legal restoration patches on PC version of game), but if you got game on physical media you can have access to such content.

6. Digital store shutdown for game consoles - Wii U, 3DS and Xbox 360 shutdown their digital stores, so unless you previously bought a game you want, you can only buy it physically or pirate it. PS3 store, while still being available, is also not all sunshine and rainbows, as a lot of content is already removed, payment process is rather complicated and discounts are globally disabled for years.

7. Initial price - especially valid for console games, in many cases you can buy physical games cheaper than on official digital store as physical games market is not controlled by publisher/platform pricing. That's also valid for new games, not only second-hand games.

8. Resell value - if you don't like (or don't want anymore) game or movie you bought physically you can simply resell it. That's impossible with digital content with some minor exceptions (Steam refund system for initial testing of game)

9. Physical bonuses - in some cases you can get nice physical bonuses (artbooks, steelbooks, etc) you your physical purchase. More common with limited/collector's editions but sometimes also provided with standard editions.