I live somewhere very hilly such that outdoor “recovery” type rides are impossible. But equally, sitting on a trainer pedalling at very low intensity for great lengths of time is almost “impossible” for me due to its tediousness.
So I walk a lot, something made easier by having nice places to walk plus a dog for me to tag along with!
Ultimately, all this bike training is about making us happier, so I try not to lose sight of that. We do this stuff that’s good for our bodies because (and more importantly) it’s good for our heads. If you choose to do low intensity outside walks, out and about in nature and enjoying the sights, sounds and smells instead of sitting indoors riding Pettit, I doubt you’ll find yourself on your death-bed one day regretting having done that. 