It's the worst in the franchise far and away - it's not even close. A lot of the improvements you mentioned were more like detriments to many as it casualized the game too much. It tried to really de-emphasize the cover mechanics, and the multplayer essentially ended up being a bunch of guys running around with a lancer and shooting without even having to aim (because the game has a transparent reticle in the middle of the screen at all times, which meant you couldn't punish players through their lag animation when they were taking the time to aim). I understand that a large part of the old Gears games was abusing the cover system to jump from wall to wall, and also figuring out how to aim the Gnasher without using the aim button, but I'd think people who've played the games can at least understand what I'm talking about. The old games made the aim button a crutch that could easily be punished and you had to learn how to not use it, and the cover mechanics had a high skill ceiling even though they were deceptively simple. I have no doubt that people most likely tried to replicate the old games in a local setting, but matchmaking was never the same, and multiplayer rarely felt rewarding.
The game launched with like four maps and while it ended up getting one or two free, it was way too late. It didn't have Locust in multiplayer. Had no Down But Not Out. It had the shittiest armor skins I've ever seen in a game, and it didn't have very many unlockable characters - which was insane considering that Gears of War 3 had so much fanservice in this department. Also even the gun skins were worse and a vast majority were microtransaction based, unlike Gears 3 (though that did have skins for sale and skin packs).
If we're only talking about non PvP content, then the game still sucked. The campaign had a shit story and no tension. It was basically just a horde mode with a loosely connected story, which is so far removed from how many unique parts where in the original trilogy. It didn't have a horde mode and instead traded it with a half baked PvP mode. And the only good campaign was a small post-game campaign that you unlock.
Yeah, it's basically not a good game in almost any way except the technical aspects. But good for you for enjoying it. I wish I could.