Best way to organize, see, & find open tabs?

I'm always frustrated when I try to find certain open tabs/windows, and that Apple's own settings don't work properly. Windows don't always line up in order, so that one I'm viewing can't always be found behind a newly opened one, something that also drives me nuts in Apple Mail. I'll be viewing one message, but if I open another, God knows where that initial one can be found! Which makes no sense...

Also, even the Windows drop-down menu won't follow orders. If I select "Arrange tabs by website", it just won't! Why not? Is it rocket science to sort them by the website, and not the specific title of a specific page?

It's these simple features not working correctly that astonish & frustrate me.

Why is there no option, usually found under the Develop heading on other browsers, for a "Task Manager" or similarly titled option, that shows a full list of every open tab, often with how much memory & cpu usage each is consuming? Why doesn't Safari have this option?

Finally, is there an extension that will allow me to see all the open tabs, so I can more easily find what I'm looking for, without having to manually scroll through every window, which is such a time-waster?