Magic mouth sees a lot of use in our games.The comprehend languages>tongues part of the example us more apt than the abstracted scepter puzzle. I don't think the scepter type puzzle is common & the comprehend languages>tongues part lights up a couple different problems. The first part related to what spells are ritual & what is not, but more on that later because it's a larger more subtle problem in the long run. The second part is that there are only about 17-18 ritual spells for wizards once you trip & the vast majority of the common use ones are first/second level (8 1st level, 3 2nd level, 4 3rd level, 3 5th level, 1 6th level). On top of being fewer & fewer from level 3+ they get more & more niche or redundant.. When was the last time you saw someone effectively use illusory script, feign death, magic mouth, or contact other plane given that the lat one can require a long rest or greater restoration unless the pc's next words are expected to be "I'm going to work, merlin is going to take a long rest here in the hotel". On top of being so few, they aren't exactly common to find those spells in spellbooks so pretty much every wizard is forced to make some of those their free spells & that leads back into the first point. A wizard who spends lets say 3-4 of their five starting spells & 1-2 of their free level up spells on ritual spells (pretty common to see IME) is going to have lots of ritual spells sure... but when it comes to combat & getting stuff done.. the sorcerer & warlock are going to have just as many of not more spells to pick from as ritual spellcasting is rarely plausible mid fight. Yes the wizard can make up for this over time by adding spells from looted spellbooks... but a lot of those will be duplicates or entirely random, "I really wish I knew acid arrow vampyric touch & faithful hound" or "I wish I had two dozen spellbooks with fireball in them" are words you probably never hear. Because spellcasters can often float between getting killed instantly & easily TPK lower level parties without even really trying with little in between a wizard is not likely to even see spellbooks early on. The warlock/sorcerer isn't going to be picking up those early utility spells for the first several levels because everyone expects the wizard to so the spells being chosen there are going to be "bread & butter things hit the fan so bad, fixitfixitfixitfixit!" solutions.. on the odd chance that you do find a spellbook, it's rarely on anything less than a cr6 mage, cr12 archmage, or some unique NPC & even if a wizard has the coin to scribe the spells, odds are good that they already have a significant chunk if not most/all of the spells in the book if the gm is pulling from published adventures (seriously how many spellbooks with the spells from the cr6 mage does one wizard need? Not to mention, how many wizards killing the cr6 mage for the first time don't already have a lot of those spells in their book for a long time now?)
Feign and Script hardly ever they are rarely chosen except for specialized concepts.
Contact plane is one of a slew of " help from beyond" that cut across many classes in tier-2. It's hot a lot of competition.
But nobody is afaik arguing there arent less useful low vslue selective opportunity only spells - they are on every list.
I do note they seem to have added divination to wizards, iirc in this UA.
But as for sorc and warlock having as many avsilsble or ehstever, nope. At 10th level its gonna be 11 known for sorc vs likely 15 prepared and maybe at least a half dozen to a dozen rituals spellbookery. With the rest-swap for wizards not bring level locked and having a minimum of 2 dozen in his spell books that he chose free - in our games that has been seen as big.
Obviously, the scribe gains will vary by campaign. I tend to assume none in my estimates or "one additional found spell of B-list caliber each character level" when I want to be generous.
Again, based on the assumptions and arguments presented, the foundations for the concern, it's pushing me more to not worry about the impact sprll versatility will have in my games or games played in our style.
For that, they were very helpful.