Just my personal opinion.
As an average user, you don't need to worry too much about whether iem or headphone sounds better, ignore all the audiophile discussions unless you are genuinely into it. The more important thing that you need to consider is comfort and if the audio quality is at least decent enough, I have tried a lot of absolute mainstream trash I wouldn't use for anything, let alone music. Once you start looking at comfort, there really is no best option but rather what you prefer or need. I personally find headphones to be more comfortable than an iem, especially on very long usage. For reference I am using an open back headphone R70x for pretty much everything and use iem chu 2 for outside/traveling. Using iem for too long gets my ears to be a bit icky which I dont face in my open back headphone.
Each headphone and iem has a different fit and may not work for all so would suggest trying it out in a store or just get something cheap but decent like chu which you can easily find around 2k or less. Although most iems tend to be neutral which is what I like but if you want something more bassy either you can try to find other cheap options or just use an equalizer. I am using Easy effects on Linux and Wavelet on Android, both are working flawlessly. Unless you have any hearing problems, pretty much any average audio gear should be good enough to hear any sound. If you really want to increase the footstep sounds then I dont see how you can get that with any device using EQ. I personally never found any trouble hearing sounds in mid/LT playing B site in Dust 2, CS2. I keep the volume pretty healthy as well so as long as there are no noise/people talking, you will hear it.
