Marxism is a living, constantly evolving science, so it very much adapts with the times.
It’s best to think of Marx and Engels as the Newton of political science and sociology… did they get everything right, and should we treat their words as gospel? Of course not, but their central tenets and ideas stand, and they built a solid foundation for others to build on.
We can recommend a lot of works on how marxism has evolved as a science, and how modern marxists view class struggle in the 21st century.