I am from EU, leftist, socialist and liberal (the left parts), and I can assure you, (a) most leftists (90%) are as liberal and antiauthoritarian as it gets, and (b) we are as powerless to change these things as you are.
Possibly, if you choose to believe me, things can change, but it's on you.
Depends on country. Here in Czechia, Communist party is one of most socially conservative one, while conservative christian party is center-left economically. Social democratic party, when it was relevant, was also pretty socially conservative, which makes sense considering their working class demigraphics.
Liberal doesn't mean supporting liberty, it means some interpolation between supporting free markets (neoliberal means just this one), and pretending that as long as we just follow the established institutional norms everything is fine and there is no need for radical change. It's synonymous right now for "centrist" - note that political labels drift over time.
Liberalism has both economic (free market) roots and political roots. The first "leftists" were the French revolutionaries and they wanted (political) freedom as well. The reason liberalism is in the "center" is because both left and right tried to appropriate it. (Although I think liberalism, in the sense of individual freedom, is a distinct value from other values such as conservative/authoritarian or socialist/communal.)
This terminology change is mostly limited to anglosphere. Outside of that 'liberal' is still commonly used for economic-right low-intervention position.
Possibly, if you choose to believe me, things can change, but it's on you.