I have played a low level Wizard actually, and I party with a low level Sorcerer in another game.
And based on your criteria on what 'sucks' at low level, the Sorcerer is way worse, as they literally don't have any options other than spamming the same spells over and over, usually cantrips.
Agreed.
The problem isn't that low level Wizards suck, it's that your spell selection sucks. True Strike and Witch Bolt have to be some of the worst spells in the game.
No doubt. It was a cool combo (when I thought it worked) and has some real potential when fighting a BBEG that the rest of the team has locked down for limited resources (especially for a wizard that did not have the Fire Bolt cantrip).
Witch Bolt does suck when fighting normal encounters, but when the wizard is doing D8 damage with his cantrips, it increase his overall damage by a lot when fighting a locked down BBEG. It's a specialty spell. In this scenario, it's 4.55 DPR round one, but 6.5 DPR every round after that (if it hit). That's slightly double the average DPR of a D8 cantrip (3.15) for a single first level spell.
Have a group of second level PCs fight a Troll and Witch Bolt suddenly shines as it partially auto-negates the Troll's regeneration. Magic Missile only negates the regeneration for a single round and then the caster is often stuck with lesser damaging cantrips again which are hit or miss. Sure, the Troll can (in many scenarios) back away from the caster (or even come attack the caster), but he eats up an OA from every front line melee PC doing so and at the same time, attacking the caster means that the Troll is not focusing fire (and is spreading out damage amongst more PCs). It's all about action economy.
Yup. A wizard with Fire Bolt could on some rounds negate a Troll's regeneration. Assuming the BBEG is a troll (and assuming the DM didn't create his own specialized type of troll). Other BBEGs? Not so much help.
Where's your find familiar spell cast as a ritual? That offers amazing utility in and out of combat, you can be a better scout than the Rogue. What about other ritual spells that don't consume spell slots (alarm, water breathing, detect magic, etc) that all have great utility while dungeoning? What about preparing spells that DON'T miss like Magic Missile? What about utilizing the best spell selection IN THE GAME (even at lower levels) to cast the right spell against the fight foe? Acid splash vs Dex save, Firebolt vs low AC, etc etc.
I did have Find Familiar. I did have Detect Magic. Neither of these really help out in a fight. Sure, the familiar can use the Help action which gives +4 or +5 equivalent to a fellow PC. But such a use of a familiar often means that the familiar gets destroyed in the fight and it costs 10 GP (not an inconsequential amount of money at low level) and a short rest (plus 10 minutes) to get it back. It's not as if wizards are not already spending a lot of gold on adding spells to their spell books (in our game, we had two wizards, so both of them were copying spells from each other at a considerable GP cost). Plus some DMs require that players buy the appropriate components for the spell ahead of time, so reacquiring a familiar at many tables might be limited to a certain number of times total when adventuring away from town.
Yes, the famiilar can be used (/abused) for Help actions and touch spells (course, some players roleplay their PCs that familiars are beloved companions to not be temporarily sacrificed like this). This means that the wizard cannot scout with his familiar and such until he gets it back. The familiar goes from being an available resource to being an expended resource.
Plus, how does one know in 5E (where combats are often 3 to 4 rounds if that) that a foe has a low Dex or a low AC? By the time someone rolls the same type of attack and rolls low and lets the player of the wizard know that a given foe is susceptible to a given attack. Yeah, mooks have low AC (but they also often have low Dex unless they are goblins). BBEGs tend to have high AC. Brutes, low Dex. There are sometimes indications, but spamming cantrips is often still boring because of the low damage. "Oh boy! I did 4 points of damage this round. Woo hoo!!!"
When a player rolls 1 or 2 total points of damage, it can be very anticlimatic. He actually hits and he often still does not contribute because the next PC who downs the foe would have still downed the foe without the extra 1 or 2 points of damage. zzzzzzzzzzzz
The issue is not using the same attack over and over again (melee classes do this all of the time). It's doing so for half the damage of other classes and feeling like the PC is not contributing much at all.
If that is enjoyable to you, great. Not my cup of tea. A lot of people write here on the boards that cantrips make spell casters fun. I find the opposite to be true. Just because you and I find different aspects of wizards to be fun (and unfun) do not mean that you are right and I am wrong. It means that our expectations and experiences are different.
In earlier versions of the game (pre-4E), wizards could not spam cantrips (or at least ones that did anything real). But if a foe failed a save (and in some editions/cases got past spell resistance), the spell contributed for multiple rounds of the encounter. The wizard contributed. In 5E with concentration and saves every round, the wizard does not seem to contribute much at all. Obviously, YMMV. And with concentration, the ability to combo spells is basically gone completely.
DM: "You want to buff the fighter and cast a non-instantaneous spell? HAHAHAHAHA You want to use two non-instantaneous spells at a time? What do you think this is? 1E to 4E???"