A recent report from Authoritas points out how volatile a Google organic search ranking is vs AI Overview ranking is. The study show that over 70% of the AI rankings changed over 13 weeks which compares to organic Google search being 55%:

AI Overview ranking volatility score: 0.68 (8 weeks), 0.73 (13 weeks)
Google Search organic ranking volatility score: 0.49 (8 weeks), 0.55 (13 weeks)

Additionally, websites within the top 10 weren’t automatically given AI Overview privledges automatically:

60% of the time, pages ranking in the top 10 appear in AI Overviews.
40% of the time, AI Overviews rank a webpage that doesn’t appear in the top 10 of Google organic search.

Bottom line: SEO has two layers: Search and AI Overviews.