Hey --- I think the problem is that people really aren't sure what you want. iCloud is a really simple photo management. It tries to do everything intelligently to stay out of your way so you don't have to spend time managing it.
I'd just send 6 photos via messenger - as long as the recipient is an iMessage user (iPhone user) they'll get good photos. However, if it is text message (SMS) it will degrade the quality significantly. Then you want to create an album and share that instead.
I personally have a 170GB photo database with nearly 2,000 videos and 82,000+ photos. Nothing seems to handle this well. I have it in a massive Photos database on an external drive. All my photos are in Google Photos - only 6,000 photos are on iCloud (35GB) and on my iPhone.
iCloud Photos is EXTREMELY SLOW with upload and download - to the point that it was going to take WEEKS to get my photos uploaded even on FIOS. So I just have it on an external drive in a Photos database (Mac). I do not have a Cloud solution to my photos as of yet - Google is managing them all very well. But I want to go to another service.
Usually when I share, I use Google Photos to share though I'm trying to get away from Google completely so I'm using iMessage more and sending actual photos through iCloud Photos - which works fairly well, especially for large albums.
I don't use photo stream unless there is a Mac involved and even then just use iCloud Photos on both and you're good.
1. How large is your photo database?
2. How often do you share photos? Is it via SMS or iMessage? Is it ever on a forum?
3. How large is your iPhone in terms of storage size? How large is your Mac size?
My Xs Max 512 GB is huge, I want to get my 170GB of photos on it but syncing photos with iTunes to my phone has failed several times and results in images I can't delete or manage on my iPhone. So I only have iCloud photos on it and will slowly, over the next year, upload my 170GB photos to iCloud.
I pay for the 1TB for $9.99/mo with iCloud.