You don't have to go through security again to go through Downtown Disney. The parks and DTD are all in the same security bubble now. You would only need to re-clear security if you went to one of the hotels.
I don't remember when exactly they changed that, but I'm fairly certain they changed that setup pre-covid.
Call me crazy, I don't honestly think it's much better or worse than it used to be. Jazz Kitchen doesn't look amazing, but it does fit the area. Mostly what's different is that a few things have rotated in and out and they've painted a bit. You're not the only person to talk about how the aesthetics of DTD were superior back in the day, but to me it's really not that different from how it's always been.
Funnily enough, I remember not that long ago people were saying that they should literally put restaurants like TGI Fridays and Applebee's in DTD to appeal to families! I guess there's no way for Disney to win there. I do think the notion of the AMC making it less of a mall is interesting, given that I have known several "generic malls" that contain movie theaters.
I guess what I don't get is that I've always seen ALL of the Disney shopping areas as glorified malls from the jump, so the notion that they were once special but now are generic is something that just doesn't make sense to me. Particularly since I feel like the place is, while not perfect, better than it has been in a long time, an opinion that it seems pretty much no one else shares with me.
Furthermore, people act like Downtown Disney is off in Timbuktu when it's directly connected to the esplanade and you can even take the monorail to it if it's too much walking. Perhaps I'm the only one who thinks that sometimes it's nice to get out of the parks for a bit and eat in a mildly less stressful environment from time to time. I get that especially if you're toting young kids around it's just not practical, but how many people here other than MickEblu are honestly doing that on a regular basis anyway?
Sure, it isn't Disney Springs, but sometimes I wonder what Downtown Disney did to hurt some of you. The vitriol and/or indifference that some express seems wildly disproportionate to the area's actual sins IMO.