While there's obviously a lot of nuance past the basic class definition. I do think that it's an incredibly useful starting point for any analysis. Looking at whether a person's primary source of income comes from their labour or from capital they own helps understand where their interests lie. I completely agree that one should not use reductive analysis here, but it's a good starting point, and it's the basis for class contradictions within the capitalist society.

Agreed, but this is moreso adding nuance to class analysis whereas the Liberals attempt to negate it entirely and say that class analysis is entirely useless and outdated. We have to go further into class analysis, get more details, information and more sophistication - where the Liberal wants us to abandon the lens entirely