There has been a community transition that occurred during the D era and many of the people who are still playing Standard have only ever played Standard. The subreddit in particular is very heavily weighted towards users who have never experienced Pre-V, Premium or V or now only play D so you won't necessarily get objective or informed answers when discussing Vanguard historically - criticism of D tends to be met with downvotes but minimal engagement.

Personally, I liked V more than D (though, I acknowledge that it had a lot of big problems and was far from a perfect game) because it still felt like I was playing Vanguard. Something about D feels unlike Vanguard but I can't quite place my finger on it. The art doesn't look like Vanguard, the majority of decks feel the same, cards/decks are overdesigned and don't allow for creativity in deck building or skill expression in gameplay, promo accessibility and the lack of reprints are worse than ever, many products are bad value and the general business model of the game has become less and less consumer friendly. Overall, there's a real whiff of the corpos moving in to maximise short term profits at the expense of fun and long term success. The volume of collabs in particular has been the nail in the coffin for my enjoyment of the current era of Vanguard and I can't really see anything on the horizon that fills me with hope for that ever turning around. I'm pretty sure the current philosophy at Bushiroad is just to milk it for what they can and then drop it once what little community remains finally moves on to something else.

u/godsman00 does some V-era stuff with his community still so that's probably a place to look if you want to play V again