Liberalism doesn't start with capitalism. This is just bad political science people on the Internet love to repeat. Liberalism revolves around the idea of individual liberty, from which the idea of property rights commonly emerges. Capitalism is arguably a corruption of some subset of these ideals, but is in no way a necessary outcome of individual liberty.
I would add that when the ideas were first conceived, property ownership was a progressive measure, as opposed to the ruling party owning all the lands.
If you take the intent behind the outcome, you get the definition I posted.
Capitalism is not a necessary outcome of individual liberty, correct! However, liberalism itself was focused on many things, such as private property rights and Capitalism itself. Liberalism is not just individual liberty.
No, Capitalism was not a central tenant of, or unique to liberalism. This is widely cited by people on the Internet but it is simply wrong. Big-C Capitalism is something which has emerged independently in the post feudal world several different times, in several different forms. The central tenant of liberalism was, in fact, the notion that individual liberty is foundational to self determination and participatory government.
The people who push the "liberalism is capitalism" trope are poorly informed leftists who naively conflate all of the evils of modernity with the dominant political mode of the era. While there is definitely a link between two, this messaging is done in an intentionally misleading way.
Capitalism is not unique to liberalism, never said it was. Liberalism is, however, a Capitalist ideology. There are many Capitalist ideologies, and liberalism is one of them.
Liberalism does effectively require some framework for private ownership, but that in itself is not a sufficient condition for Capitalism. My issue with what you are saying is the conjecture that you cannot have socialist economic structures alongside liberal political ones, which is the (incorrect) dogma of many online leftist spaces. You can have collective ownership of labor (in various forms), while still owning a house or a suitcase or a jacket, while also being an actualized participant in liberal democracy.
If you're aware of leftist belief, then you should also be familiar with the concept of personal property, and the difference between it and private property. Additionally, you can have a representative democracy based on modern liberal Democracies with a Socialist structure, but you're trying to pretend that liberal democracy is liberalism.
You cannot have Socialist economic structures alongside liberal structures, this is the correct take.