Yes, the limitation is irritating. I imagine we will see individual voice recognition in the not too (relative) future.
We have Google Home, and have had it since Christmas 2016. When we first got it, there were many of the same "assistant" limitations on calendar's etc. In fact, initially with GH, you could not even add things to your calendar (this was also when it was limited to just a single account too). Looking at it from this perspective, HomePod has this from the beginning. You could not send and listen to text's either at launch on the GH.
Google was as capable then to allow for these features, and did not have them at launch either. The calendars (being able to add) came in the spring time if I remember correctly. Multi user came in the summer I believe.
I suspect, before Apple (and Google at the time) rolled out more enhanced features, they wanted to make sure kinks on the released problem are worked out.
I will say that the sound is great, and I cannot ever make my GH sound nearly as good. Th HP and HomeKit work great (better than GH) for what is available on HK. Granted, there are many more products available with GH than HP, but Apple is opening up HK more in the near future. In the meantime, running HomeBridge has given my HP access to all home automation that GH has.
Hardware wise, the HP is much better than GH, software will catch it up (and potentially better). I know now, we use "Hey Siri" much more than "OK Google" to control items in our home. IT works faster too.