Why my deposit is less than my sales

Stripe's card fee (2.9% + 30¢) comes off each card payment; the transfer to your bank is free.

Every card payment (including Apple Pay and Google Pay) has Stripe's card fee taken off at the moment it's paid: 2.9% + 30¢. On a $180 sale that's $5.52, so $174.48 lands in your bank.

The transfer to your bank is free. It arrives about 2 business days after the payment.
Cash has no fee.
Hotseat takes nothing out of your card payments. The shop's Hotseat bill comes separately.
Booth renters take card payments on their own Stripe account, so the card fee comes off their own sales. On a commission chair, the shop pays it.

To see each payment and its fee, open your Stripe dashboard from Your settings → Pay in & pay out.