I think that it is so sad that you feel this way OP. I am in my 60's (and yes I do have the excuse of bad health, but I do a lot of non-grocery on-line shopping, so no excuse really), and once my children reached their teens I asked them if they would prefer me to buy them presents, or give them money, luckily for me, they chose money. If you add up the years that I spent shopping for birthdays for all of them, it adds up to about 45 years worth of birthday presents, and that was just for their birthdays. For Christmas they all get money now (the same amount each for them and their partners), but if any are staying over on Christmas eve they also get about 12-15 presents each from Santa - I had 4 adult children staying over last Christmas (because we had been living together during lockdown). I love giving them the Santa presents, they choose to ask Santa for one each, and the others are smaller, and some of them just silly fun presents. However, after Christmas I am exhausted from all the choosing, ordering, keeping a record of, hiding and wrapping them; I know that my ill health won't let me do this for much longer, but I hope to do at least a few more years.
Sorry, I have gone into too much detail here, what I am trying to say is that the Mum part of me who bought their presents when they were children, and made their themed birthday cakes, was running out of steam a bit by the time they hit their mid teens (obviously not just with birthdays and Christmas, I felt that if I never had to make another packed lunch for school in my whole life, it would be too soon!) I was worn out. I could never stop trying to be or wanting to be the emotional support they need now they are all adults (whilst I am still compos mentis at least), but the physical aspects of child rearing are sadly behind me (because of my illnesses), most people in their 60's can of course go on much longer than I can, but maybe like me, some were very grateful when their children either told them that they would prefer money for their presents, or when they, the ageing parents, quite reasonably assumed that their children would prefer to have the money to buy their own treats.
That I now get very thoughtful presents from most of my children, one has mental health problems and doesn't usually get me anything, is absolutely lovely, they don't seem to resent that they now only get money from me.
I wish you didn't resent your Mum OP, as you imply that she shows her love in other - and I would say - much more important ways.
By the way, I still bought, hopefully thoughtful, gifts, for my parents and in-law, until the last one sadly died in 2019, in her 90's! I was always so grateful to get money as presents from my parents and in-law, even though when my children were young, the money usually went to pay bills, or get things for the children.