GNOME: user-local .desktop applications don't show in menu

[JohnTheCoolingFan]

I decided to "install" a couple of AppImage applications so that I don't have to use them through the file manager. I unpacked the image to get the .desktop file, put it in $HOME/.local/share/applications/ and also copied the icons to $HOME/.local/share/icons. I then moved the AppImage to my $HOME/.local/bin/ and changed the .desktop file to use the AppImage, without a full path, just the executable file name. The applications did not appear in the gnome menu, but gtk-launch started them just fine. From my search I've discovered that it's an issue of $HOME/.local/bin/ not being in $PATH that gnome uses. I've tried to do many things to add it to the $PATH, but none worked.
I am using a systemd profile, so first I tried to put a file in $HOME/.config/environment.d, but it didn't work, the value didn't change even in systemctl --user show-environment. $HOME/.profile and /etc/profile didn't work too.

Now I moved the executables to /opt/bin/, which is in $PATH and the applications now show up. But I would like to be able to use $HOME/.local/bin/ and I find it weird that the attempts to alter the $PATH environment variable didn't work. What do you think might be the cause?