Not sure what yahoo has other than email as I’ve “looked them up.”
But you are correct apples’ iCloud services are frictionless. And if you want to backup your photos some advance planning is needed, especially to avoid lock in.
Yahoo has email, contacts, calendars, reminders, and notes. Same as Google.
When I said 'frictionless', I meant third party services to
me.
As far as photos with Apple, that has friction for me. I take a picture on my iDevices and to get it on my Macs, I have to open the Photos app and pull it out. Of course, it syncs to all my Apple devices and Macs, but it's all stored in iCloud unless I pull out individual pics.
That's why I use Dropbox for photos. Take pic, open Dropbox, the automatic Camera Uploads feature kicks in and the new photo uploads as a file (jpg or heic) to the Camera Uploads folder inside Dropbox. So, at that point, on EVERY device I have running Dropbox, that file (image) is immediately present.
On my Mac, it means I can periodically pull images from the Camera Uploads folder directly to my NAS. Which means, all those images get backed up - because my NAS gets backed up. And yes, they exist also in Dropbox's cloud. But ALSO PHYSICALLY on hard drives, SSDs and devices that I have running Dropbox.
I don't have to open another app to pull them out. They are physically present right on my Macs drives and all my devices.
I have a 2TB iCloud sub, and I got it because I broke an iPhone and wanted to put all my images in iCloud back on my replacement iPhone. It's solely for convenience.
Guess what? iCloud didn't restore everything. I had to physically go back and drop in all my backed up images that DROPBOX had saved back in to the Photos app on my Mac to get them to ALL show back up on my iPhone.
That is not frictionless.