I didn't know about batch transactions! Should definetely take a look at that.
I suggest you look at the example of freebitco.in, they offer three withdrawal methods: Instant (variable fee, currently ~$ 0.24), Slow (batch transactions every 6 hours, low fee - currently ~$ 0.06) and Auto (weekly payout, batch transactions, low fees).
Avereage fees for bitcoin these days are about 3$ which is too high from my perspective in my early stage of website.
No. I don't know where you got that number. Those fees are too high.
Take a look at mempool.space:

I have sent 1 sat/vB transactions for the past few months when I am not in a hurry, and they have always been accepted.