My kids are tweens, but I thought the same thing. In truth, what happened to me (may you be more fortunate) is that daycare prices went up pretty much at the rate my kids aged into “less expensive” programs. So I had a pretty consistent daycare bill until the youngest was in full day Kindergarten - at which point we used the schools before/after care which was about half as much with two kids. When the youngest was in third grade we started to let them come home on the bus to an empty house for an hour (an empty house with stay at home neighbors and a large dog) - which cut it in half again. My son started middle school last year - half again. My youngest is about to turn twelve and go into middle school. My last daycare bill ever was in June.
So in 1999 I had two kids in the infant room for about $1600 a month. (my kids are only a year apart, my daughter was born in 1999, my son in 1998). When they both were in the toddler room, I was down to $1400 a month for a whole month, then the price increase hit and I was back to $1600, repeat at preschool - I paid about $1600 a month until my daughter was six, when I started paying $800 a month though the school for before/after care. When she was nine I started paying $400 for two in before school care. The last year I paid $200 a month.
IME daycare expenses will be a lot more than you believe for a lot longer.
(ETA, we moved daycare costs to college funds - plus all the school fees, band, piano, baseball, gymnastics - as they decreased, so I still have $1600 a month going into the kids’. I’m hoping they get cheaper when they actually leave the house ;)).