My children are 18-23 yrs old. So my experiences may be a bit dated. But they went through the College Station Aquatics swim lessons starting at around 4 yrs old. Two of them became WSI Aides at 12 and Red Cross certified WSI at 16; teaching during the summer seasons. It was a great way to earn $$ while in high school and college. The other child decided she didn't want to teach and joined the summer swim team (Tsunamis) for a few summers instead.
We didn't have a pool of our own and private lessons weren't widely available when they were young. But I was very happy with what my children experienced with CS Aquatics lessons.
Unfortunately, I know there has been significant leadership changes in CS Aquatics (RIP Vera) since my kids were younger, so I am glad there are other options now.