Saw a tweet on here (can't find it now) stating something along the lines that capitalism was an improvement from feudalism and that this view is the basic Marxist position. This is very linear and undialectical in my view.

Capitalism emerged as the dominant mode of production as an ascendant merchant class gained economic importance & thus political cohesiveness to challenge the feudal nobility. But this class struggle did not result in feudalism's total defeat.

The thinking that capitalism (or any stage of production) is/was an inevitable outcome negates class struggle as the engine of history. It explains the outcome by means of the outcome, which taken to its logical conclusion means the Big Bang logically leads to bipedal apes.

What I mean here is that over the 100s of 1000s of years of human development, the stages or modes of production were not foregone conclusions, but products of certain preconditions and evolving or emerging conditions, within and outside of human control.

Socialism is one outcome of capitalism. It's true that capitalism is a necessary precondition for socialism. And capitalism is quite literally reaching its natural limits. But it is not certain that socialism or communism will necessarily develop.

Nuclear holocaust, environmental collapse, fragmentation of society to a degree where the relations of capital breakdown which also make socialism impossible, etc. are also possible outcomes.