I miss Picasa so much. I switched to Lightroom but I hate the subscription model and how heavy it is. I just want a light fast way of managing 500k photos and d

I miss Picasa so much. I switched to Lightroom but I hate the subscription model and how heavy it is. I just want a light fast way of managing 500k photos and doing basic edits. Rotate, crop, export at specific resolutions for sharing, tagging, etc. I appreciate the power in Lightroom but I just don't need it. Also, I'd love to switch to Linux full-time but that's the main program I'm lacking. I've tried most the suggestions but none handle high numbers of photos without becoming intolerably slow.