We are in the same boat. Getting on in age. Hey, we qualify for seniors discounts!
My wife has a low stool that she sits on to tend the garden, so no kneeling.
In the green house we have raised beds, so easy planting & harvesting.
She likes to have a lawn, so she pushed a lawn mower around for years (before the wife, the yard around the house was part of a hay field, so I mowed it once a year)
when the push mower got to be too much work, we bought a ride on mower.
I try to use a machine for all the farming work, mostly works except for firewood, theres still a lot of stoop and carry there.
We quit making small square hay bales a couple years ago, getting young help on short notice is tricky.
Sold all the equipment used to make them so I would not be tempted.
Now we make only large round bales, and the tractor handles all the lifting and stacking just fine.
We use a post pounder to install fence posts, and usually rig up a way of carrying and unrolling fence wire off the truck or 4 wheeler.
Instead of pounding in thousands of staples (I have elbow & shoulder issues) I use aluminum straps made for BX cable, fasten them to the wood post
with wood screws and a battery powered impact. Works well.
We do our own machinery repairs here, so we have a shop to do them in.
When working under vehicles got old like me, I bought a 2 post hoist (not that expensive really)
It can lift our full sized trucks, really makes life a lot easier.
The way we have things laid out around the farm, I shovel very little snow in the winter, can clear most of it with the tractor loader & 3 pt. snow blower.
We hope to keep farming well into our 70's