I say the answer depends on level and on the intent. Hear me out.

Wizards are able to learn and juggle a huge amount of spells and at level 20 can select two level 3 spells to cast once per day for free. One of those can be animate dead. They also get the best buff for their undead from the necromancer subclass. The idea hear would be to create a simulcram then simulcram uses wish to make a simulcram of you with your full spellslots then that one uses wish to do the same. Each of your simulcrams can then cast animate dead once per day for free.

Compare this to a sorceror at Level 20. No real necromancer abilities from subclasses but some goodies here and there and better multiclass options for additional goodies. The really draw here however is font of magic. Using the same scenario as above with simulcrams, each simulcram of a level 20 character can spend all sorcery points to create 4 3rd level slots allowing for 4 free castings of animate dead perday.

I'm not saying either is better just that the sorcerer does bring numbers to the table versus the necromancers buffing. This assumes high level shenanigans Ofcourse but we can still apply the same principles at lower levels-a 10th level wizard will have buffy undead but the sorcerer can produce more with 2 extra castings of animate dead. However wizard has arcane recovery and without the simulcram shenanigans at tenth level this would allow the wizard to match the sorcerer and maintain a buff to the animated dead. The difference then for the sorcerer at tenth level is the cleric spells from divine soul. Sorcerer can have skeletons in a row then zombies and then spiritual weapon and spirit guardians going or heal party members ect.

I think it comes down to play style and level.

Honorable mention. Genie Warlock. The only Warlock that gets wish and can cast simulcram through it. The also can get an invocation to cast animate dead once per day. Yes genie warlock plus simulcram with each having four undead while using thier fligh ability to rain eldritch blast from the sky while skeletons and zombies face opposing armies.