Yeah, I don't agree that Bloodstained is the better game. For personal comparison, I put about 80 hours (maybe 90, I can't remember now) into RotN on Game Pass, during a free three months I had; I cleared the game 100%, and collected/synthed just about everything aside from getting 9 of the boss shards (requires repeat playthroughs). I would absolutely never play it again, though. For Shenmue III I have a current play time of about 150 hours, and would play it again tomorrow.
I don't mean to say that RotN is a bad game (obviously I wouldn't have put that much time into it if it was), but it was pretty underwhelming. I much prefer the classicvania-styled games (CV, CV3, Rondo, Bloodlines, X68K, Rebirth, in particular), but SotN is a defining classic, and probably my favorite game in its subgenre. So I get why RotN seemed to try to feel like something of a remake of SotN, but with Order of Ecclesia glyphs. Broadly speaking, RotN fairs all right with it, but really falls down on the details. First of all, I don't care how it's dressed up, great 2D, hand drawn graphics will always look better than 3D rendered graphics. RotN doesn't look bad at all, but I find it kind of lifeless, visually, and suffers from that kind of Vaseline look UE4 has at times. As an extension of the 3D rendering, the main character's attack timings are-- "idiosyncratic" I guess would be the diplomatic way to put it. The base weapon delays for most weapons are pretty awful to begin with, and basically railroaded me into using boots until I got the Yagrush. Optimizers start to open up other weapon types, but that's pretty near the end of the game when you can get them. The main offender is the delay in being able to attack when landing from a jump. It basically makes the player a sitting duck for half a second, and is my biggest actual complaint about the game. (Also, shards are stupidly OP, and pretty much break the game very early on.)
Overall, RotN just isn't as well designed as SotN, and doesn't offer any compelling reason for me to play it instead of just replaying SotN. Something that I think is really amazing about SotN is the amount of attention put into unique enemy death animations and sounds. It's kind of a hold over from Rondo, but it adds a lot of character to everything you fight in Dracula's castle. RotN, understandably, just has enemies fade out of existence, and the only really unique parts are when the chain and sickle enemies have their chain links flying around the screen, or the legs on the bugs outside the tower area stretch from one corner of the screen to the other (theses are unintended, by the way). As much as I like games with female protagonists, the story in Bloodstained is pretty uninteresting to me, also, and it doesn't have the benefit of tying into themes established by a decade's worth of previous games in the series (not to mention being a direct sequel to an all-time great game in Rondo).
I wouldn't even say RotN is the best metroidvania I've played that was released in the last ten years. Guacamelee! and Ori were both way better, in my opinion. Michiru Yamane still does great work, though. A lot of the soundtrack is pretty great, especially "Gears of Fortune." "Forgotten Jade" is almost as good as "Lost Painting," too.
Shenmue III, for me, is a far more polished, ambitious, and fun game. I know it's a sacrilegious suggestion for some, but I actually enjoy playing Shenmue III more, in a lot of ways, than I do the first two games, and I'm someone who personally most wanted the kickstarter to be for a Shenmue III exclusively on the Dreamcast.
About the sales, I'm not really that surprised, and I honestly don't think Shenmue III will ever hit those numbers. I'd love to be proven wrong, but price differences aside, these games were playing by two separate sets of rules. The bar for Bloodstained was only a couple of inches off the ground. Shenmue III had to hurdle a 30 foot wall. There's no sizable contingent of the gamer-space that takes every opportunity it can to tear down SotN, like there is for the Shenmue series. Iga's 'vanias were always the mainstream of mainstream. I didn't bother supporting the RotN kickstarter, because I knew it would have no trouble hitting the mark. Conversely, I was very surprised that Shenmue III even got over the initial funding mark. The first game may have been a million-seller, but it's always demonstrated a dichotomy between people who "get it," and those who don't. For those who don't it's a 'trash walking-sim with nothing to do.' For those who do get it, it's often the greatest thing ever. The two sides have rarely been able to reconcile these differences. Frankly I feel the group that doesn't get it has always been the more mainstream group, and that's why you have outlets reviewing Shenmue III as a 3 or 4 out of 10.
I'm not sure the metacritic score really hurt Shenmue III's sales, per se, but I'm sure the more generally negative scuttlebutt about the game that went along with it did. I also don't really understand why Deep Silver and/or Suzuki wanted to push Shenmue III as a AAA game. I'm sure Deep Silver was looking at it in terms of getting holiday sales, but there was no way SIII was going to be able to compete with the biggest releases of the year. Also releasing it for full-price MSRP was probably a mistake. It sort of seems like Deep Silver was just getting greedy, but for all I know Suzuki could have wanted to do it that way.
Hindsight's always 20/20, though.