Which RPG System to Use? RPG System Impact on Play Style? It Depends...
Many people can get rather "religious" about which is the "best" role-playing game system. This is pretty much a "Chevy vs. Ford Vs. Dodge" type argument. Some systems are going to appeal to different people in different areas for different reasons.
This conversation focuses on tabletop RPG systems. The game systems for LARPS can make a huge difference in the experience, especially because of the added safety and other complex issues of the LARP experiences.
Also, the dumbing down of most systems writing level over the past 15-20 years may have an impact on the level of benefits for enhancing reading ability that previous research showed in this area (as well as math).
It is a good thing there is NOT a one size fits all solution. The diversity of ideas in RPGs is wonderful!
Also, while it is true that "in the wild" different game systems do appear to impact play style notably, we have observed over the decades that it is MUCH more about the Game Master (and the players) personalities and play-style preferences, and the campaign setting, than the game system rules themselves. You can have a "murder-hobo" heavy group, or heavy story-based group using D&D because of the factors outside of the system completely changing how the players make use of the system. This is not any special flexibility of D&D, it is observed with just about any system. Though self-selection definitely factors in, as far as individuals and those they want to play with, and system options available and chosen. Furthermore, with professionally structured approach to oversight and methodologies in place, such as using Therapeutic Recreation (TR) principles, it is almost entirely the GM and the setting that has the greatest impact on play style (as well as the individual players of course). The game system differences can be almost completely negated by enough of these much stronger influencing variables. This often is caused by common house rules tweaking the system in the direction desired by the GM, which most RPGs do encourage.
Some systems, like Warhammer FRP I have dubbed "the nanny system" due to its approach, which may be appropriate for less trustworthy groups of players, while others are much more trusting and encouraging of positive behaviors without strict oversight, such as The One Ring RPG are ideal for building comaraderie quickly, although the ultimate for comraderie building (before even making any characters) would hands down be the House Building rules from A Song of Ice & Fire (Game of Thrones) RPG, which I have adopted with great success to other settings (like Greyhawk).
Over the decades we've experimented with many different systems and with a very wide array of populations. From 2 years old to 80+ years old, from populations not requiring any adaptations to those with significant factors requiring considerable adaptations. Generally we make adaptations to any system for specific client needs, as needed, and with that approach, any system works roughly as well as any other. We usually don't bury participants in the rules up front, instead letting them jump in and start playing right away, and they learn the rules as they play the game. Later if they wish, they can delve into the depth of the rules, when they are ready.
Especially since we emphasize encouraging participants coming up with non-combat approaches to problem solving, encouraging players to focus on ROLE-playing over ROLL-playing, and the rule "Story trumps rules" (though it needs to be handled in a consistent and predictable way, especially for those with high anxiety levels that manifests as "rules lawyers"). We definitely allow combat, but we tend to make it more "deadly" than the default, and they quickly become violence adverse and instead look at it only as a final option only after all other options have been exhausted.
We have found that the setting and the GM style are MUCH more important than the system rules themselves. It is not that they don't have an impact, and in non-TR-controlled settings the systems do often lead to very different play styles. With TR methodologies applied the system specific rules have much less impact on play style, and generally very little deterrent in achieving the educational and therapeutic goals, while everyone still has a wonderful, fun, immersed, flow-state encouraging, experience with role-playing gaming. The point is, that although some systems are better at emphasizing certain play styles, from the TR perspective we can make pretty much any system work to achieve our goals for the clients educational and therapeutic goals, so we don't have to get hung up in a debate on which is "the best system".
One important note however. It is MUCH EASIER to take even the "crunchiest" of systems (Rolemaster for example) and easily, without much rules modification, focusing more on play style than rules changes, and make it a richly "narrative" style ROLE-play experience. It is more problematic to take a "rules-light" system (Firefly RPG) and make it "crunchy" (easier to strip away/ignore than to add), without either adding rules from other systems, or making up a lot of rules from scratch.
Some systems are arguably easier to use for targeting very specific goals (education, therapy, etc.), but with the exception of the few little-known systems specifically designed for those goals (Cryptomancer for example), they all work in roughly the same way.
So, ultimately, focus more on the setting and play style you enjoy most, and use whatever game system you enjoy. While some may be more professionally slick than others, ultimately, if it works for you, then enjoy your favorite system, and let others enjoy theirs'.
Ultimately what really matters most is that those playing and GMing the game are having fun!