Buying a physical copy of a game is still faster to download than digital so I don't understand what your getting at. The download would take even longer if you bought it as a digital title.
Halo 5 has had amazing post launch support. Each month they've added new content to the game for free, and they still are. A new update is releasing tomorrow actually with new maps, modes, weapons, skins, features, etc. So yeah, it does suck you have to download a 41GB update, but would you rather spend money on each DLC released or wait awhile to download the full game? I would pick the later.
I also advise to buy an external harddrive. It's nice not having to worry about storage. My 5TB harddrive cost $120, not a bad price. Plus it can be used for a number of other devices as well.
Btw this isn't just an Xbox One issue. PS4 and PC have to download huge updates as well. Some larger than others. MS just has really done a great job with most of their 1st party games as far as post-content support goes, Halo in particular.