Reading this thread is somewhat amusing. As probably the one guy who has worked in more facets of aviation than anyone else here, from civil to military to CFI to 135 to 121, both fixed wing and rotor wing and CFI in both; I’m in the camp of “it depends” and “nether is better than the other”.
So far as CFI or not route, I did both when I started out. Part time CFI while also flying traffic watch. Was good, but at the time I lacked experience, not being significantly more experienced than the people I was teaching. I personally have never liked the SERGRAD or FAIP model, having experienced that in the military later. Was a good way to build time and experience, but I wasn’t able to teach from a high level of experience back to the student, being not very experience myself at this time.
Moved up to single engine part 135 cargo, VFR then IFR, while still instructing part time. Was able to slowly start bringing more background of experience to the table to pass on.
Moved up to multi engine and turbine part 135 cargo, while still part time instructing, being able to bring even more quality of instruction, although still limited to certain areas of experience, but still better and improved experiences both for myself as well as to pass along.
Went military, tactical jet fighters. Brought past experience to the training which when applied properly and in the right areas, while not conflicting with the military way of aviation training and learning, paid off well and added to the SA bag of tricks. Did part time CFI again post-initial training, and began to feel that I was having more and more quality and wider range of experience to give back to students.
Flew tactical jets for a decade including combat, in some high tech stuff in high performance flight regimes being a military IP in the process. Transitioned to rotary wing military, and to rotary wing civil, as an IP and CFI also. Was still a part time CFI on the side, mainly doing IPCs and BFRs and such, but feeling much more comfortable in what I was giving back.
Do the 121 thing part time, flying both seats of a 737. Very good experience for both the type of flying, although 121 flying itself is boring as hell......but, it’s supposed to be. Not the flying I enjoy, but a good experience to have and one that helps with CFIing in terms of experience and instruction to pass on to students.
Now, as rotor wing pilot, CFI and line check pilot; I look back on instructing in my early days, and it was a great experience, though now I’m able to give back far more to students than I was able to then.
But the point is, it’s not really a this or that, there’s nothing precluding doing both CFI and regular flying. Both are good ways to learn and develop oneself, and with CFI at least begin the process of teaching early on with what you know, even though with low experience. But, if there is no desire to teach, that’s fine too....there’s no requirement to be a CFI as a prerequisite to anything besides CFI jobs; it’s a nice to have, but not necessarily a need to have. And it’s not for everyone. Though I personally think it’s a good experience, one has to want to do it.