Seems like some boots are missing

One thing Ive always liked about the game was the boots mechanic and concept. You can only wear one pair of shoes people I mean cmon. Theyve always been a small way to keep diversity in builds, and with the recent removal of enchantments I started thinking about my favorite part of builds again. And I got to thinking, seems like some stats are missing representation in the boot category. I thought it might be a wonderful way to replace the lessened diversity by covering a few already missed basis. So far weve got the: basic bitch boot gotta move fast boot gotta move hella fast boot gotta shoot fast boot gotta do more stuff boot gotta hurt more boot gotta take less dmg boot gotta keep moving/cant stop me boot

Is there a reason that there are not: flat AD/AP boots? Armor Pen boots? and the one that bothers me the most is the lack of HP boots. HP seems like such a good stat for boots and tanks to add into the diversity. Now a days it just buy mercs. Oh they have a riven and a twitch/jinx/etc then buy tabi. idk just a thought.