It is absolutely more accessible, with more varied playstyles, even if it lacks z-levels and the worldgen.
For a certain usage of accessibility focused on UI; Rimworld's still about 30 USD with that 20% sale, while ASCII DF is still, y'know, whatever the bandwidth you spend on downloading it costs
The steam editions are comparable in price, but DF's more or less full featured shareware with the (steam) buy-in being UI/graphics related.
... if you include modded stuff, though, I'm not sure the playstyles
are actually more varied for rimworld? With adventure mode and all the nonsense DF's own modding scene throws in, at least as far as I've noticed it's fairly comparable.
DF doesn't really expect you to have a massive colony, in any case. You can (most of the time I've played it through its life, I
have just due to hardware limitations on my end that have only eased up a little recently) play small forts without much trouble, only missing out on some of the higher nobility interactions at worst (and iirc you can adjust the numbers on those so they do show up when you only have like 20 critters or whatev'). DF allows and ecourages higher numbers, but the game plays more or less fine with just a dozen or two dwarves or whatev'... even less is
viable, but it does start getting pretty harrowing without a good few replacements on hand in case of funtimes, heh.