I was brought up equally by my parents and one set of grandparents who lived a mile away from my home. My mother had a life-limiting health condition with regular flare-ups which meant I stated with GPs regularly. As a child my family were skint but I never knew that and didn't really realise how unwell my mother was until she died when I was 18. Her illness was never allowed to impact my childhood other than fostering a caring but resilient approach to obstacles in life. I'd describe my childhood as pretty idyllic really. I knew I was loved and cherished. I was happy and secure with so many people I could turn to.
I really, really wanted that for my own DC but sadly my parents and grandparents all died before I had my own children (twins) with a man who also had no family and whom I subsequently left when the babies were newborn (he turned out to be abusive once I was pregnant). He's not been involved since. I had a lot more advantages than many single parents because I have great friends and a reasonably well-paid job but I felt/feel so, so sad for my children missing out on the sort of grandparents experience that I had. I was also exhausted from doing everything myself so much of the time.
I like to think I protected my now adult DC from the harsh realities single parenthood can bring in the same way I was protected by my own family about my mother's illness. But I recognise that it would have been hard for my mother to provide that protection and that she could not have done it without my dad and my grandparents. I know how much it cost me to try to cushion my own DC in the same way and the nights I sat up til the early hours working, trying to ensure I could pay the mortgage, feed us and still send them on that school trip when I could only afford 4 days childcare not 5.
My DC tell me they have great memories of their early childhood. I remember fond moments but an awful lot of stress. I'm glad they didn't pick up on it but a part of me feels a bit cheated of just being able to enjoy them.
Whether I'll become a grandmother remains to be seen. If I do, whether my DC live close enough to play an active role also remains to be seen. If I'm still working myself and whether I'm fit enough to look after children are other variables. There's a lot that can influence the future. However, what I do know is that if I'm able to be closely involved in my grandchildren's lives nothing will stop me from doing just that.
I love my DC. Wanting to look after them and protect them doesn't change once they're adults. They are remarkably self sufficient young people who don't take me for granted and are very caring and considerate so I know they won't take the piss. I want to remain close to them as we all get older and I want them to enjoy their own DC as much as they can, not struggle as I did. I can provide regular childcare and still have my own life and be free to travel when I choose. It's fine to refuse, but relationship quality is set by the effort you put into them in my view. Not seeing /communicating regularly with your DGC is bound to result in a less close relationship than one where you're significantly involved. That said, quality not quantity also matters.
I've never subscribed to the view that the past was a perfect place. Some families are frankly awful and best escaped from and women in particular were often stifled and overburdened. However, when families worked well this really benefited mothers and children. Successive governments have encouraged people to move to chase jobs, and in doing so have decimated extended families and all the support they offer. They have not filled that gap with affordable childcare or supported initiatives aimed at promoting new social support networks. Family doesn't have to mean blood or traditional structure. It could be a close group of friends. Regardless, it's largely mothers and children who suffer for a lack of support in my opinion. I don't want that to include my own DC and DGC when I can do something about it and in turn experience the joy of close family relationships without the downsides of regular sleepless nights etc.
We're all different but so get what you're saying OP. I just wouldn't phrase it in terms of morality as there's nothing immoral about putting yourself first in your later years, particularly if you've made many sacrifices beforehand. It's a choice that's all.