Specifically in the UK or in general worldwide?
In 'western'/first world society -
Unequal expectations of responsibility of household management/life admin/caring duties within relationships/families.
Everyday casual sexism infantilising women and constantly implying we are intellectually and physically inferior, valuing us for appearance and attractiveness over ability and personality. So we believe it. It is deeply ingrained in all of us. Gendered expectations.
Neglect of women's healthcare, safety, needs in design etc - the assumption being that the average body is male, so everything from new medicines to the height of seats in bus shelters are designed for the male body, not the female.
The acceptance of male violence and victim-blaming culture. Whilst assault and abuse is illegal, there is widespread social acceptance of male aggressive tendencies and an attitude of women must not provoke. More gendered expectations.
All of this persists despite equality laws supposedly meaning that there are no inequalities between the sexes any more.
Obviously, there are still many countries in the world where equality law doesn't exist, women's lives are absolutely horrendous on the basis they are female and it is all legal - lack of access to education, healthcare, maternity care, rape within marriage, forced births, forced marriage to rapists, forced marriages full stop, so-called honour killings, female genital mutilation, women being unable to work, unable to drive or travel freely, unable to wear clothes of their own choosing, men being legally entitled to beat their wives, stigma of victims of rape, or divorcées, etc.