You're assuming product people don't 'invent' work, which is faaaar from true. The more technical the area, the more nonsense 'product' generates, that engineering then has to either redo, clean up or fight. The 'product' people on 'product-led' teams also generally own the internal comms and marketing (internal) side of things, which often has the effect of silencing engineering (and many other negative side effects). (Not always but often imo)

Engineers should understand their customers and their product (whether internal or external), should understand their metrics, and should be able to make intelligent, informed decisions. Sticking a non-technical 'product' (aka marketing) person into the mix is generally net-negative imo.