The funny thing about this chart is that it seems to detract from your "overvalued market" thesis rather than supporting it. Like, it basically says the market's valuation is average, except for tech and financials. And tech, considering its size, is growing insanely quickly with super-high margins right when the world gets transformed by the creation of AI.
In fact, it feels like it undersells the positive impact of AI on non-tech companies, if they're only trading at average valuations. So it suggest that the broader market is average to cheap.