I will answer your question by the two sides you laid out:
>in modern first world countries, these "limits on access to education" simply don't exist in the way they did in revolutionary Russia, China, etc.
This is true to an extent, public schooling allows even lumpens the ability to learn at least basic knowledge on a range of subjects.
With that said, the fact still stands that to go out of your way to stumble onto and then go on to research Marxism in it's theory and history in any great depth you need to have a good amount of time and energy to bother taking up the task.
I am approaching this from the current situation in the imperial core (what I assume you're talking about) where Communist are universally anaemic and can barely attract college students let alone the working and lumpen masses.
Marxism and all that is connected with it will never be taught in public schools nor will it be exposed to the general public as anything less than a bogeyman with the usual anti-communist rhetoric ('good in theory but….').
The lack of access to education is not the same as it was is in semi-feudal societies, yes, but it's still present in more subtle way; you may have full access to key Marxist texts to read in print or online as we do, but again most don't have the sheer willpower after a hard, draining day's work to push through a dense text with archaic, academic language when they could instead veg out to TV or scroll through social media.Post too long. Click here to view the full text.