The only things E7 has on 7DS that I think 99% of the people agree on is its engine and its RGB pity system for all banners. It's a wonderful engine that supports an absolutely stunning artstyle, and the pity system is frankly "too" generous, which is why they monetize the game in other ways (mostly stamina and mystics).
- 7DS lets you change gear without spending gold. And it has "sets" that you can easily swap between characters with a single button press.
- 7DS lets you reroll gear substats very easily and cheaply. The highest tier requires a limited resource, but it is not difficult to come by once you hit end game.
- 7DS doesn't have 15% RNG bullshit. Sorry, but that 15% means the game will never, ever be balanced. PVE is a nightmare and PVP is an exercise in frustration.
- 7DS has developers who actually listen to criticism and respond. The most recent criticism was in regards to their changing the login/daily rewards and two days later they implemented changes to appease the playerbase.
- 7DS has unlimited auto repeat, with stamina being very similar to GBF. Game just poops out stamina potions. Some may see this as a negative, but E7 is the same way in that you need to grind repeatedly, and since we're only comparing the two, this is a positive in its favor.
- 7DS has packs that you don't feel bad buying. E7 had some pretty neat $29.99 packs, but for some reason, those just...vanished.
- 7DS has a stream of PVE content, whereas E7 has had next to no content for 8 months. This has changed recently in favor of E7, but for E7 I want to see them make new challenging and engaging content, not content that was promised last year.
7DS has stats on cosmetics, but you are limited to five slots, and you can very easily get equivalent stat gear simply by promoting the units. I honestly don't know why they have stats. Seems like maybe they thought about making it P2W and then backtracked, but left them in. It's an odd thing to see.
The only reason to compare the two is because they are INCREDIBLY similar, outside of the combat which is psuedo-card-turn-based in 7DS and turn-based in E7. Never understood why people compared DL and E7, but here the games are cut from very similar cloths. You farm gear then level gear with RNG substats while farming catalyst-like materials to promote and awaken your units.
Note: This is only comparing the systems. Things like art, story, gameplay, etc are all subjective. And you are in no way wrong for liking one thing over another. Go for it. But after seeing the 1:1 systems in both games, E7 is just embarrassing. And for me, personally, the systems are why I play gacha games.