It's completely deliberate. In 2020 the head of Google Ads, Prabhakar Raghavan, led an internal coup that saw him installed as head of Search. Basically this was because Google Search was doing its job too well and not enough people were being forced to click on ads. Since then he's done everything he can to enshitify the serps so ad revenues go up.
https://www.wheresyoured.at/the-men-who-killed-google/