I've only seen season 1 so far, but I thought I heard the story of season 3 stuck much closer to the manga? Season 1 had the changes to the Shitennou's deaths (and changed the Beryl fight a lot, and skipped all the extreme horror imagery like Usagi's nightmare about Mamoru with no skin), and I thought I heard season 2 changed things a little too, while Season 3 supposedly didn't alter the story much.
Art-style wise I don't feel like any of the seasons really matched the look of the manga.
I can't speak to the overall success or what the companies are thinking, but, I would find Crystal a lot more interesting if they'd tried to make it a "best of both worlds" continuity, grabbing unique ideas from both the manga and the '90s anime and blending them together. Like keep Zoisite and Kunzite's present day relationship but then include the past life romantic link with the Inner Senshi, or have the Naru and Nephrite story while also going into the backstory about them being Endymion's guardians and tie those threads together somehow, and then put some new spins on these combined ideas that weren't featured in either continuity. They could even grab some things from the live action continuity, which is it's own insane third path; basically, I think this would've been a good time to make a 'super continuity' that borrows from everything and ties it together. Sort of like Sailor Moon: Another Story was trying to do, but more developed.