In fact, Court did face the best players of her time at the AO. This is a list of multiple Grand Slam winners who participated at the Australian Open between 1960 and 1975:
1. Lesley Turner Bowrey (2 times Grand Slam winner): participated in 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974 and 1975.
2. Evonne Goolagong Cawley (14 times Grand Slam winner): participated in 1967, 1968, 1969, 1970, 1971, 1972 1973, 1974, and 1975.
3. Maria Bueno (7 times Grand Slam winner): participated in 1960 and 1965.
4. Billie Jean King (11 times Grand Slam winner): participated in 1965, 1968 and 1969.
This is Court's H2H at the Australian Open over other multiple Grand Slam winners of her time:
Court leads Bowrey 2-0.
Court leads Goolagong 4-0.
Court leads Bueno 2-0.
Court leads Jean-King 2-1.
Total= Court leads 10-1 the H2H over multiple Grand Slam winners.
In sum, the best players of Court's time did participate at the AO. Court never participated at the AO without having at least one multiple Grand Slam winner in the draw. Court leads the H2H over multiple Grand Slam winners 10-1. That's brutal domination and strongly suggests that is has nothing to do with a supposed "weak competition". Court was simply the best. I repeat, she leads 10-1 the H2H over multiple Grand Slam winners.
Logico-methodological conclusion: Court has 24 Grand Slams and is the women's GOAT.