Indoor cat..quality of life?

I recently lost my guy to the coyotes. I live adjacent to a
forested area where they are active, so I am thinking my next best
friend should be confined to quarters

I have been reading the many compelling arguments in favour of
keeping a cat inside---the safety angle, longevity cf to the
free-rangers, etc. I know there is much one can do to make indoor
living tolerable to a cat, such as cat tree, cat grass munchies, toys,
etc.

But I am still wondering what the consensus here might be to
just how pleasurable life really is for an indoor cat, Or am I just
anthropomorphizing human traits onto a cat, and they really don't need
as much stimuli in a day as we do, especially when they sleep 15-plus
hours out of every 24? What about the second-cat-to-keep-the
-first-one-company option?

Thanks for your input.

Blair Thompson
North Vancouver, B.C.