The wizard, without needing anything, is the most powerful* class in the game. They do NOT need handouts.
There are several things that I think are wrong about your question, but primarily you seem to have a player who wants to play to a specific niche. As with a niche, doing so means they are going to be less versatile, and versatility is the wizard's biggest weapon.
You could give this player every wizard spell in the game, but if they are going to chose revivify over hypnotic pattern, slow or fireball, then that is their choice and not a problem with the wizard list, or the cleric list.
That said, here are some of my observations about the classes from years of experience playing and reading
The wizard spell list is AMAZING.
Healing in 5e is WAY overrated, as to a large extent is spell damage. The wizard has the most powerful spells in the game, and they are the control spells. Hypnotic pattern can make a deadly encounter with multiple enemies into several easy encounters. Revivify may let you bring back the dead, but if the cleric had hypnotic pattern and cast it in advance that death would probably have been avoided.
There are also plenty of spell preparation slots and spell choices that let you have your cake and eat it. I play a divination wizard, and similarly to your necromancer every time I level up I always pick a divination spell (where available) plus one useful other spell. I have more than enough awesome spells that I still have to put thought in each day on which spells to prepare, and have a spell for every situation I have encountered so far.
Giving me access to spell scrolls wouldn't help me much, the only scrolls I would really be interested in are rituals, because they would directly impact my power without costing me preparation slots. However that is just a direct buff which my character does not need.
The cleric spell list is quite poor after 3rd level
Revivify specifically is a tax on clerics, and they often end the day with a 3rd level slot left just in case. Not casting that spell likely meant one encounter was harder than it could have been, the party probably took more damage as a result, and the cleric might even have spent lower level slots on healing damage that wouldn't have been inflicted in the first place if they weren't afraid to use a 3rd level slot - or more specifically if they had been a wizard and had access to control spells.
I took a look at the 4th level spells at random. There are 8 (compared to 34 for a wizard!). Banishment is often thought of as powerful, but outside of targeting a rare save it does less than hypnotic pattern, which is a 3rd level wizard spell. The other good spells are divination (a ritual which wizards also get) and death ward which is another spell that you probably wouldn't need to cast if you were proactive with control spells.
The rest such as control water, freedom of movement and locate creature are somewhere between situational, very situational, and poor. And outside of a few standout spells, and people who over-value healing, it doesn't get much better.
Clerics standout spells are spiritual weapon and spirit guardians. These are low level spells that allow a cleric to wade into melee and cause damage. That is the strength of a cleric, but tops out pretty quickly.
I have played a cleric, and rather than agonising about which amazing spells I would have to not prepare today (like my wizard does) I was thinking 'which of these situational spells do I pad my preparation slots with?'.
Clerics allow for players to correct their poor spell choices every day, a wizard rewards (or even needs) forward planning and an understanding of the options
The only thing going the clerics way is that is the player makes a poor choice in preparation they can just pick better spells the next day. The wizard player on the other hand is stuck with their 2 picked spells unless the DM lets them change. That puts the onus on the player to understand their spell choices. I consider this a pro rather than a con, because knowing stuff is good.
If your player has a problem picking the right spells you are better off letting them swap spells when they level up or something similar rather than giving them more spells. But personally I would tell my player to put some effort in and learn their spells - I actually have a rule that spell casters in my game MUST know their spells, and I do test them occasionally (new players get a pass while I teach them).
*Figured I would explain my use of powerful. A wizard might not win a fight on their own, but they are the biggest force multiplier in the game, and that is where the true power lies in a game like D&D which is a resource management game at heart. A well played wizard lets other players do more with less and really makes the melee characters shine.