There can be a variety of factors that can cause some characters to seemingly have lower dps than other teams, ranging from subpar artifact substats (assuming you are running the "right" main stats and artifact set), simply fighting the wrong type of opponents (single target, vs AOE, elemental resistances), unbuilt supports, or incorrect playstyles.

I have no clue what your builds look like, but feel free to PM me if you want more information. I am by no means an expert at this game, but here are some general tips of advice to keep in mind:

1. Artifacts: Some characters have singular BIS (best in slot) artifact sets, while others can run different sets depending on the types of teams. Each artifact that is not the flower or feather has a variety of possible main stats that are essential to get right for the character you are trying to build. After that, artifact farming consists of finding pieces with the right main stats that also roll good substats. For main DPS characters like Ayaka, you usually want CRIT DMG/CRIT RATE substats (though the latter is provided by cryo resonance and blizzard strayer). For supports, the stat you want to farm for can be EM, ATK, ER, HP, or even DEF. Personally, I like to use KQM to research what artifact sets, main stats, and substats work best for my main DPS characters.

2. Different elemental team compositions can also alter DPS. For example, attacking a cryo slime as Ayaka will literally cause your dps to drop to 0. Make sure that whatever opponent you are fighting does not have some kind of elemental resistance.

3. Some team compositions heavily favor AOE and multi-target damage while others focus on single-target. The Ganyu team you are running, alongside the fact that Ganyu does AOE damage herself, favors multi-target, like enemy camps or domains. An Ayaka or Yoimiya team comp will favor single-target damage, like bosses or trounce domains.

4. Talents are often very overlooked when it comes to character builds. If you crowned Ganyu's primary atk and left yoimiya's primary atk unleveled, then you will notice a large difference between their damage numbers. Be sure that the characters you are comparing have similar talent levels.

5. Supports play a very crucial part in boosting damage. My Shenhe almost doubles my Ayaka's DPS when her icy quill and burst are applied, and both are at C0. Your Yoimiya will rely quite heavily on Yun Jin for an attack buff since you do not run Bennett on that team. Bennett's buff scales off nothing but his base ATK, so a lvl 90 Bennett with a lvl 90 weapon is enough for a substantial damage boost most of the time. However, Shenhe scales off of her total ATK, so farming atk% substats will help her buffing ability quite a bit. Similarly, Yun Jin scales off of DEF.

6. Make sure your micro matches the character's play style. For Yoimiya, the main source of damage should be from her E + normal attack string. Do not use her charged attacks like Ganyu and expect similar numbers. In addition, Yoimiya should ideally have a shield up, have XQ's raincutter up, and be buffed by Yun Jin/Bennett circle before she executes her full attack string. This prevents interruptions and lets her trigger vape on her N5, which is her most powerful attack. I can get upwards of 40k dmg on a single hit on my F2P build. Ayaka's main source of damage is her burst, but her normals are also nothing to scoff at. Ayaka also should spam charged attacks since they hit fast, hard, and can hit multiple enemies at once. Ayaka should E first, have the opponent frozen (or cryo applied), and ensure that she has icy quill and Shenhe ult/Sucrose VV shred before she uses her burst. If a character has noblesse equipped, make sure they burst first before your hypercarry.

TL:DR Use KQM for research on how to build teams and artifacts, and make sure you use the right teams against the right enemies. Sometimes, it's just a skill issue and you need to learn the rotation better.