Not having all skills is the most outdated thing ever. If you must have this hugely out dated system within the game then it should just be to level spells from 2-3 and have them cap at level 2 until you find the book.
There is lazy players who want everything on a plate, there are casual players who really enjoy it but will struggle to actually achieve everything within the game, there are players who play a good amount of time every night and will eventually achieve everything within the game, then there are the no life/pay too win players who will always achieve everything fast.
The regular/no life players will always want an advantage over all other players, which is why spells will always be the old way, if everyone had all spells all hell would break lose. This means the casuals have to deal with only ever getting spells a year after everyone else has them, which by that point you would expect new spells, they will always be 1 step behind and never experience everything the class has to offer.
Until everyone gets all spells there will never be "good" players, higher end spells have such a huge impact that whoever has them first normally dominates until a lot more also have the spells.