Why don't we see quantum effects in everyday life?

Because writing a record erases them, and large objects are recorded constantly. In OPH a measurement is the writing of a record, and writing deletes every comparison between the possible answers, which physicists call decoherence. OPH's repair law makes this exact. Each repair attempt shrinks the coherence between different load arrangements on a carrier's seams to at most a fixed fraction of its size, so after many attempts only a classical reading is left, and the longest-lived datum a carrier holds is a position-like readout. A record that steers what an observer does is kept as a classical record, with its alternatives fixed, while the quantum comparisons between them need not survive. A chair is recorded without pause: every photon and air molecule that leaves it carries where it was, so copies of its position are made continuously. An isolated electron, or a cold and shielded experiment, stays unrecorded long enough for its alternatives to interfere.

Also in Chapter 28: What Is a Particle, What Is a Wave, and Why Does It Look Like Both?, Chapter 16: Why Does Time Run, and Only One Way?.