That’s a good point. I have both the Springfield XD9 in the 4” and 3” barrel. I occassionally carry the 3” subcompact, but only in a belt holster with a loose fitting jacket or blazer. It does not conceal well on me in a pants pocket or with more form fitting clothing. The revolver, in contrast, conceals well in the front pocket of my cargo pants/shorts and chinos, or in a holster worn IWB or OWB with a sweatshirt or even an oversized polo shirt or untucked workshirt.
I have it easy. I carry in my purse, so no worries on the size or where to conceal. I have the XDM 40 and love it.