I have been playing both modes for a few years now, and here is my breakdown:
Gameplay/realism: both games certainly have their flaws here, but i would say madden more so than the show has some issues that aren’t getting addressed. Stadiums, player likeness, equipment, are all better in the show. The presentation is better in the show.
Content: while both modes recycle legends/promos to a large degree, I will give madden the upper hand here. Madden has better themed promos, the show feels more rinse and repeat with the inning system. With theme team boosts and more legends for lesser known teams, I think madden excels in this area. The one edge the show has is the ability to earn superior cards without spending a dime. Some of the best cards are free
Market/binder: The show has a superior market setup to madden imo, although this is kinda personal preference. However, maddens card binder is far more easy to navigate in my opinion. This is pretty much a matter of choice.
Solo play/challenges: madden revamped their solo challenges this year, and with solo battles as well giving good rewards. The show has showdown, conquest, moments, etc. both modes cater well to solo play
Online competition: madden offers more variety of online play (solo, draft, squads, WL) than the show. Madden is more annoying online and you experience more cheese than the show, running into meta schemes and animations. There are some signs of RNG/DDA in both modes, but I find more in madden than the show. Madden hurt the quality of play with abilities and X factors badly this year. I prefer maddens season format to the shows, however the show offers more transparency for ratings.
Servers: Both kinda suck tbh and could use work
Developers: EA is less willing to listen to players and make immediate change than SDS I feel. Pack odds are questionable in both games lol. Both teams have work to do. EA tries to steer players towards micro transactions more so than SDS
Final verdict: both modes are fun, however with their own flaws. I like both a lot. I do play more madden, as I just feel a football video game will always be a little more fun than a baseball video game, but I’m glad they both exist.