JiffyPopTart
Bree-Yark
as many already asked, why?
Wizards learn more spells per level that they can prepare and they can prepare more spells that they can cast.
Is it ritual casting?
Will those few 1-3 level spells extra that can be cast as ritual really be a problem?
Is having party with water breathing 24/7 a problem?
Or hauling gear on Tenser's floating disc instead of a cart, a problem?
Not to pick on you specifically because you aren't the only one to say it...but why ask why? The OP clearly stated they wanted to look at making a change in copying spells to get a different feel for spellbooks in a campaign and asked for suggestions on how they could make that happen. Isn't that reason enough?
There was some meta discussion talk a couple months ago about establishing a framework on how to tag your thread as "Constructive Only" and it's not really happened yet...but man it would be nice if people could refrain from threadcrapping on everything they don't like or see a need for.
It's not constructive to point out "Who cares if all the wizards share the same set of spells". It's obstructive and contributes nothing to the topic except derailing a creation thread into one that low-key tells the OP "Your idea sucks."