You are in the minority. Role playing is not about dialogue choices and different reactions, and never was, even going back to the original D&D and Wizardry. I have no idea why various people keep making posts claiming dialogue has anything to do with role playing when it simply doesn't and this can be seen throughout the history of role playing games, both physical and computer.
Now, if we are talking about Japanese visual novels and adventure games, as well as hybrids including some RPGs such as the Langrisser and Growlanser franchises, then yes, dialogue is a key element as well as different reactions and outcomes based on dialogue choices. However, that is a different genre of gaming, although I have suggested that these games perhaps might be better considered genuine RPGs than the many games that are classified as RPGs.
The differences for different plays are not standard for RPGs, either, since many RPGs are generally linear and focused on telling a specific story about specific character(s).
However, if you are concerned about differences, then the fact is that RPGs, particularly Western RPGs, focus on the way you build your character initially and how the character is developed during the early to middle stages of the game. Playing a stealth-focused character who uses little to no armor is completely different than playing a hulking brute who wants to plow through everything in Power Armor using as big of guns as can be found.