I work in technology/computers and I’ll probably keep my mechanical SPG because of how many idiots and stupid business practices I see in the industry. I’d be less worried about my computer dying as it giving me wrong numbers. I’m sure facts would prove me wrong though, probably computers are as reliable as mechanical, but diving is a lot about peace of mind and confidence also.
As far as having to end your dive if your computer fails... I agree mostly, but if I’m diving in my home area in a protected bay with max depth of 30’ and planning a 20’ depth for 45 minutes max... I will not dive without my SPG, but would have no issue diving without my computer. If I was diving 100+ depth I’d have two SPGs, digital or analog, probably one of each.