I'm mostly talking about how the design of the set itself felt like more safe than I would have liked. Where the original ravnica defined what these two color combinations are and gave them character the new set and mechanocs did almost nothing to expand on the definitions that were solidified over the last 5 years.
Oh, I agree that RTR was the definition of "playing it safe" from a design standpoint, and GRN seems to be following the same pattern, but honestly I am totally okay with that, I feel like the time between RTR and GRN has been a series of "design experiments" that have all backfired drastically. BFZ was just garbage all around (a terrible set in a vacuum, and also the heralded in an era of 4-color manabases in standard as we had both fetchlands
and fetchable duals in rotation at once, leading to every deck splashing for flip Jace and turning him into a $80 card). And Kaladesh was a nightmare from a design standpoint, requiring WotC to roll out the standard banlist for the first time since Zendikar's infamous JTMS + Stoneforge Mystic ban: when Aether Revolt dropped, a whopping
three cards had to be banned right out the gate, followed immediately by an emergency banning of the Saheeli + Felidar Guardian combo after the set had been out for a day on MTGO, then a half year later Aetherworks Marvel got banned, and was followed
again by
another ban a year later to ban the cards that were making the energy archetype busted.
Right now, the standard ban list contains a whopping
seven cards, five of which are from Kaladesh block, and the Kaladesh bans came in three waves and
four separate ban announcements to deal with four different problem decks that popped up as a result of cards that were fundamentally flawed in their design. (I hate, hate,
hate energy and it baffles me that MaRo continues to defend this parasitic mechanic by saying that energy's issue was just that it wasn't properly costed.) And mind you, that's not even in the rear view mirror yet, that seven-card banlist is the standard environment
right now and having just endured two years of the utter nonsense that was Kaladesh block I am more than okay with it if design wants to "play things safe" and stick to the fundamentals as they did with RTR. (And I can definitely see why WotC would want to move in that direction, too.)
I remember TCC predicting that the 2018 fall set would be Return to Return to Ravnica because Hasbro wanted something that was "corporate safe" after what had been several bumpy years (it's also a popular plane making it a easy sell from a marketing standpoint) so I think going back to Ravnica was a pretty sensible decision all around. Much like MrE I also kinda had the reaction of "it's kinda soon to be going back to Ravnica" combined with the realization of "wait, RTR was 2012, and it's 2018...so I guess it's been longer than I thought," and I'm pretty sure this is mostly because even though six years have passed, BFZ and Kaladesh both feel like these "blurs" of time, like how Kaladesh block was only "six months" but really it felt like it defined two years of standard and in standard it just feels like certain blocks have been swallowed up by the black hole that was BFZ and Kaladesh's design failures.
Going back to Ravnica again (when RTR-THS was the last standard format that I think a lot of players felt really good about) combined with the recent Dominaria and the return of Core sets with Core 19 actually feels like hitting the "reset" button on what has kind of been a 5-year nightmare of standard formats, so all in all I feel pretty happy to be going back to Ravnica!