Thankfully, gardening is something you can do as you decide. Expand on your successes, abandon failures. I still see people showing pics and discussing things I've never seen or heard of before.
I've never done some of these things, like clean a tool. But I'm not finished yet, I've only been gardening for a few decades. It could happen.
Many of these list items are things I do, if I have the plants (no trees bearing fruit yet, never encountered a perennial Mum if one is gauging by performance, not what it says on the label) but rarely during summer unless absolutely necessary, like watering when it hasn't rained in a while.
It's way too hot to anything that can wait, like mulching or pruning woody entities. There are too many plants covering most of the space where I would mulch, so that has never been something I would do in summer even when I lived farther north where I was outside all day every day during summer.
For me, stocking up for fall mostly means saving every glass bottle and jar I can find to save cuttings in water for a few months of winter. And on the very rare occasion when I see curbside bagged yard waste, grabbing it to bring home to be spread as part of the mulch when it cools off. And making sure I have enough plastic plates to use as saucers for potted plants that will be brought in just before first frost. Not big enough for some pots, and not clear, but so much cheaper than buying the saucers in the pots section. Probably not what most gardeners are doing, but it's what I want to do, and how I want to do it.
Gardening is so diverse, other people's to-do lists may or may not apply to what you are doing and growing, conflict with your style or goals, and if your location is different from the location of the list, the timing may not be appropriate for your location. You can learn so much and get so many great ideas that may work for you too by reading and seeing what others are doing - especially on this forum site. Keep an open mind about trying new things, especially if you are less than 100% satisfied with what you have already done.