iMessage is the worst messenger on iPhone

Where can I ask Apple to improve iMessage? It is lacking SO SO much! All of my improvements request are features that other messengers have:

Voice messages

• There is no easy way to scroll through them. Ugh!!!
• You can't adjust the playback speed (which is great when listening to your parents' memos..)
• Once you leave iMessage the playback stops, so you have to keep your phone awake & have iMessage open. Terrible!

History / Library

• The media library doesn't allow to easily scroll through media sent.

(I have WhatsApp Media Library that goes back 10 years and I can scroll through without a problem)

• The media library gets glitchy, sometimes it doesn't properly show older media sent
• Once you actually find a picture in the media gallery, you can't click on it to find the context in which it was sent.
• When you're out of reception / in a plane and want to write messages that should get delivered once you have reception again, that won't work either
• No way to easily set the delivery quality of pictures (e.g. WeChat allows to select "full quality" or just the regular quality that is usually enough for communication)
• When I select lower quality picture mode, they sometimes just arrive as a thumbnail

--> The list is MUCH longer, but these are points that should be easily addressable!

I can't be the only one that realizes, that iMessage is BY FAR the worst messenger on iPhone. Apple Watch is the only reason why I have to rely on it.

These improvements seem so simple to make for a developer like Apple, what's the hold up? Who has answers as to why it is such a terrible app? Am I not seeing something?