Vehicles under $15k are 1.6% of the market, and their share of the market has dropped over 90% since 2019. The old advice that you can get a beater and drive it in to the ground for $5k hasn’t been true for years but it still seems pervasive in personal finance spaces.
I’m curious what safety features in particular you consider necessary? I ask because all of the modern stuff you list (blind spot monitoring, brake assist, lane keep assist, adaptive cruise control) I’d argue are hardly necessary for anyone. Blind spot monitoring can be replaced by a $10 pair of blind spot mirrors and everything else is more of a convenience feature or something that can be replaced by instilling good habits into your teen about keeping attention on the road and not getting distracted with her phone or fiddling with the radio.