I was going to reply to your previous post, but never got to it; It's how it works. You're not supposed to have access to other users' folders and files. The two obvious ways to share between accounts is 1. The "Shared" folder in /Users folder, that's available to all users, and 2. connect a second drive to the mac, or create a new volume on the existing one, they will also be available.
(The "Shared" folder is most often filled with files that applications install to let all users use the same apps and have the apps' files, libraries etc be installed only once and not in each user's folder, but you can also use it to share files between accounts. Creating a new volume is super easy on Apples' APFS file system; in Disk Utilities, select Macintosh HD, click the 'plus' sign, give it a name, and it will show up and be available to all users. Volumes are not partitions, but behaves the same way mostly. One big difference is that you don't have to set a volume's size like you do with partitions. Volumes on APFS take only the space they need. IOW, they 'share' the free space. Really nice.)
I've never seen or heard of anyone doing what you did to the user folder permissions. I know how to change permissions and use the 'enclosed items' function, but doing it to the whole user folder… I'm not sure. MacOS sets up the folder structure and permissions the way it does for a reason, and it expects to find it that way. F.ex the music app expects to find a 'Music' folder in your user folder, and if it's not there, it will create one. I wouldn't expect your adding permissions for your account on another user's user folder (and enclosed) to create problems, but one could perhaps view it as a potential vulnerability securitywise. Anyway, I suppose in your starting phase now, it would be easy just to delete the user account (system settings - user/groups) should you run into any problems.